Proficient At, With, or In? Learn Preposition Use in English

Language precision matters. The subtle difference between saying "proficient at coding," "proficient in coding," or "proficient with coding" might seem inconsequential to many English learners, but these preposition choices reveal deeper linguistic patterns that impact communication clarity. The challenge of selecting the right preposition after "proficient" represents a common stumbling block even for advanced English speakers.

Why does this distinction matter? Because precision in language signals competence. When professionals describe their skills on resumes, during interviews, or in workplace communications, the preposition they pair with "proficient" subtly shapes how others perceive their expertise. These small linguistic choices build credibility—or undermine it.

This guide examines the nuanced differences between "proficient at," "proficient with," and "proficient in," providing clear guidance on when to use each construction. By understanding these distinctions, you'll communicate more precisely and project greater language mastery.

What Does "Proficient" Mean?

Before diving into preposition usage, let's establish what "proficient" actually means. The term "proficient" describes a high level of competence or skill in a particular area. It sits in the spectrum of expertise somewhere between "competent" and "expert."

When someone is proficient, they demonstrate:

Advanced capability beyond basic competence
Consistent performance without frequent errors
Independent execution without constant guidance
Practical application of knowledge in varied situations

Proficiency implies mastery acquired through deliberate practice and experience, not merely theoretical knowledge. Consider these examples:

An accountant proficient in tax law applies complex regulations correctly across various client situations.
A programmer proficient at debugging identifies and resolves code issues efficiently.
A teacher proficient with digital learning tools integrates them seamlessly into classroom instruction.

The level of skill indicated by "proficient" typically requires significant time investment—often described in frameworks like the "10,000-hour rule" popularized by Malcolm Gladwell, though actual timelines vary significantly by domain and individual.

Overview of Prepositions With "Proficient"

The three primary prepositions used with "proficient" are "at," "in," and "with." Each carries subtle semantic differences that native speakers intuitively understand. For English learners, however, these distinctions require explicit attention.

When to Use "Proficient At"

"Proficient at" typically refers to activities, tasks, or skills that involve active performance or execution. This construction emphasizes the action itself rather than the broader knowledge domain.

Common Usage Patterns

"Proficient at" most commonly pairs with:

Specific activities requiring physical or mental engagement
Skills involving action or performance
Discrete tasks with clear parameters

Examples in Context

She's proficient at negotiating complex contracts. (Emphasizes the activity of negotiating)
The new employee is proficient at troubleshooting network issues. (Focuses on the specific task)
After years of practice, he became proficient at public speaking. (Highlights the performance skill)

Notice how each example involves a dynamic activity rather than a static body of knowledge.

Analysis of Language Patterns

Corpus linguistics reveals that "proficient at" frequently appears with verbs in gerund form (the -ing form functioning as a noun). This pattern reinforces its connection to active processes:

proficient at analyzing
proficient at managing
proficient at solving

The construction aligns with how we discuss active abilities in other phrases like "good at," "skilled at," or "expert at."

When to Use "Proficient In"

"Proficient in" typically refers to broader fields, subjects, or domains of knowledge. This construction emphasizes comprehensive understanding of a field rather than specific active skills.

Common Usage Patterns

"Proficient in" most commonly pairs with:

Academic subjects or fields of study
Languages and communication systems
Professional disciplines or domains
Bodies of knowledge or theoretical frameworks

Examples in Context

The candidate is proficient in data science. (Refers to the entire field)
Many Swiss citizens are proficient in multiple languages. (References language systems)
The consultant demonstrated she was proficient in healthcare regulations. (Indicates domain knowledge)

Each example references a comprehensive area rather than a specific activity.

Analysis of Language Patterns

Corpus analysis shows "proficient in" frequently appears with noun phrases representing fields, disciplines, or systems:

proficient in mathematics
proficient in Spanish
proficient in business management

This pattern parallels other constructions like "knowledgeable in," "educated in," or "specialized in," all of which reference knowledge domains rather than specific actions.

When to Use "Proficient With"

"Proficient with" typically refers to tools, instruments, technologies, or methodologies—concrete things that someone uses or applies. This construction emphasizes the relationship between the person and the instrument or system they utilize.

Common Usage Patterns

"Proficient with" most commonly pairs with:

Physical or digital tools
Software applications or platforms
Equipment or machinery
Systems or frameworks used instrumentally

Examples in Context

The designer is proficient with Adobe Creative Suite. (References software tools)
Surgeons must be proficient with various medical instruments. (Indicates tool usage)
The analyst became proficient with statistical modeling software. (Describes technology application)

Each example involves something the person actively uses as an instrument to accomplish goals.

Analysis of Language Patterns

Usage data indicates "proficient with" frequently appears alongside specific named tools, platforms, or systems:

proficient with Excel
proficient with CAD software
proficient with laboratory equipment

This pattern parallels other tool-related constructions like "skilled with," "familiar with," or "experienced with."

Overlap and Grey Areas

While these guidelines capture general patterns, English usage isn't always perfectly categorical. Some cases legitimately allow multiple prepositions with subtle meaning shifts:

Proficient in Python (emphasizing knowledge of the language)
Proficient with Python (emphasizing using Python as a tool)
Proficient at Python programming (emphasizing the activity)

Context often clarifies the intended meaning, and native speakers may switch between prepositions based on the aspect of proficiency they wish to emphasize.

Common Mistakes and How to Avoid Them

Non-native English speakers frequently encounter challenges when selecting prepositions to pair with "proficient." Understanding these common errors can help avoid them.

Incorrect Preposition Choices

The most frequent errors include:

Using "of" instead of appropriate prepositions: "Proficient of" is always incorrect in standard English. This likely stems from translation interference from languages where the equivalent construction uses a genitive case.

Incorrect: He is proficient of three languages. Correct: He is proficient in three languages.

Confusing "at" and "in": Using "proficient at" when referring to knowledge domains or using "proficient in" for specific activities reverses the standard pattern.

Incorrect: She is proficient at economics. Correct: She is proficient in economics.

Incorrect: He is proficient in playing chess. Correct: He is proficient at playing chess.

Omitting necessary prepositions: Some learners incorrectly drop prepositions entirely after "proficient."

Incorrect: The technician is proficient computer repair. Correct: The technician is proficient in computer repair.

Context-Dependent Challenges

Some scenarios pose particular difficulties because the correct preposition depends on subtle contextual distinctions:

Language proficiency: While "proficient in Spanish" is standard when referring to overall language knowledge, specific language activities might use different prepositions:

Proficient in Spanish (general knowledge)
Proficient at speaking Spanish (specific performance)
Proficient with Spanish literature (engaging with materials)

Technical domains: Fields involving both knowledge and application can take different prepositions depending on emphasis:

Proficient in cybersecurity (field knowledge)
Proficient at detecting vulnerabilities (specific activity)
Proficient with security tools (using instruments)

Industry-Specific Conventions

Certain professional fields have developed their own conventions for preposition use with "proficient":

Healthcare: Medical documentation often uses "proficient in" for procedures and "proficient with" for equipment.

Technology: Many tech job descriptions specify "proficient in" for programming languages but "proficient with" for software applications.

Academia: Scholarly contexts typically prefer "proficient in" for subject areas regardless of whether they involve active skills.

Using "Proficient" in Professional Contexts

The term "proficient" appears frequently in professional communication, particularly in job-related contexts. Using it correctly with appropriate prepositions strengthens your professional image.

Resume and CV Usage

On resumes and CVs, "proficient" serves as a valuable qualifier when describing skill levels. The preposition choice signals specific aspects of your competence:

Skills sections typically use simplified formats:

Proficient in: Data analysis, project management, corporate finance
Proficient with: Tableau, SQL, Microsoft Project
Proficient at: Public speaking, conflict resolution, strategic planning

Work experience descriptions often incorporate "proficient" into achievement statements:

"Developed training for team members to become proficient in regulatory compliance procedures."
"Utilized proficiency with advanced modeling software to reduce design time by 30%."

Research by resume analysis company Jobscan found that 62% of hiring managers consider precise language in skills descriptions a key factor in resume evaluation. This precision includes appropriate preposition usage.

Job Descriptions and Requirements

Employers signal specific expectations through preposition choice when listing requirements:

"Proficient in" typically appears with:

Educational requirements: "Candidates must be proficient in quantitative analysis."
Domain knowledge: "Seeking applicants proficient in international trade regulations."

"Proficient with" commonly appears alongside:

Technology requirements: "Must be proficient with CRM platforms, particularly Salesforce."
Tool specifications: "The role requires someone proficient with audio editing equipment."

"Proficient at" often describes:

Performance expectations: "The ideal candidate is proficient at managing multiple priorities."
Process skills: "We need someone proficient at troubleshooting complex systems."

Understanding these distinctions helps tailor application materials to employer expectations.

Language Proficiency Frameworks

Professional language assessment frameworks have established specific conventions for describing proficiency levels:

Common European Framework of Reference (CEFR) consistently uses "proficient in" when referring to language levels (B1, B2, C1, C2).

American Council on Teaching Foreign Languages (ACTFL) uses "proficient in" for overall language ability but may use "proficient at" when referring to specific skill areas like speaking or writing.

These conventions influence how language skills are described across international professional contexts.

Subtle Meaning Differences Between Prepositions

The choice between "at," "in," and "with" carries implications beyond grammatical correctness. These prepositions shape how others perceive the nature and extent of your proficiency.

Psychological Perception of Different Prepositions

Research in psycholinguistics suggests preposition choice influences how listeners conceptualize expertise:

"Proficient at" implies active mastery demonstrated through performance.
"Proficient in" suggests comprehensive understanding and theoretical foundation.
"Proficient with" communicates practical, applied capability with specific instruments.

A 2018 study in the Journal of Experimental Psychology found that subjects rated individuals described as "proficient in" a field as having more theoretical knowledge, while those described as "proficient at" specific tasks were perceived as having more practical expertise.

Nuances in Different Contexts

The subtle implications of preposition choice vary across contexts:

Academic settings typically value "proficient in" constructions that suggest comprehensive subject mastery.

Performance-based environments like sports or arts favor "proficient at" to emphasize execution capabilities.

Technical fields often prioritize "proficient with" to highlight practical tool application.

Consider how these differences play out in parallel examples:

The researcher is proficient in statistical methods. (Suggests comprehensive understanding)
The researcher is proficient at analyzing statistical data. (Emphasizes performance capability)
The researcher is proficient with statistical software packages. (Focuses on tool application)

Each construction positions the individual's expertise differently.

Impact on Communication Effectiveness

Choosing the appropriate preposition enhances communication precision. When preposition choice aligns with the intended meaning, messages become clearer and more effectively conveyed.

Inappropriate preposition selection can create subtle disconnects:

A job candidate claiming to be "proficient at accounting" when the employer seeks someone "proficient in accounting principles" might be perceived as lacking theoretical foundation.
A team member described as "proficient in project management" when stakeholders need someone "proficient at meeting deadlines" might not meet performance expectations.

Precise language builds credibility. According to communication effectiveness studies, speakers perceived as precise in their language choices are rated as more competent and trustworthy.

Practical Examples and Comparisons

To solidify understanding of these distinctions, let's examine sets of examples that illustrate the differences between preposition choices in various contexts.

Professional Skills

Software Development:

Proficient in software architecture principles (knowledge domain)
Proficient at debugging complex code issues (activity)
Proficient with version control systems like Git (tools)

Healthcare:

Proficient in anatomy and physiology (knowledge domain)
Proficient at conducting patient assessments (activity)
Proficient with diagnostic imaging equipment (tools)

Education:

Proficient in pedagogical theory (knowledge domain)
Proficient at assessing student learning needs (activity)
Proficient with classroom management techniques (methods)

Language and Communication

Written Communication:

Proficient in English grammar and syntax (knowledge domain)
Proficient at crafting persuasive arguments (activity)
Proficient with style guides and formatting standards (tools/frameworks)

Public Speaking:

Proficient in rhetorical principles (knowledge domain)
Proficient at engaging diverse audiences (activity)
Proficient with presentation technologies (tools)

Technical Fields

Data Science:

Proficient in statistical theory (knowledge domain)
Proficient at identifying meaningful patterns in datasets (activity)
Proficient with Python, R, and visualization tools (instruments)

Engineering:

Proficient in mechanical engineering principles (knowledge domain)
Proficient at designing efficient systems (activity)
Proficient with CAD software and simulation tools (instruments)

Same Skill, Different Emphasis

Notice how preposition choice shifts emphasis even when discussing the same general area:

Marketing Focus:

Proficient in marketing principles (emphasizes theoretical knowledge)
Proficient at developing marketing strategies (emphasizes activity)
Proficient with marketing analytics platforms (emphasizes tools)

Financial Analysis:

Proficient in financial modeling theory (emphasizes knowledge domain)
Proficient at forecasting market trends (emphasizes activity)
Proficient with Bloomberg Terminal and financial software (emphasizes tools)

These examples demonstrate how precise preposition selection clarifies exactly what aspect of proficiency is being highlighted.

Regional and Cultural Variations

Like many aspects of language, preposition use with "proficient" shows some variation across different English-speaking regions and contexts.

American vs. British English Differences

While the general patterns described earlier hold across major English varieties, some subtle preferences emerge:

American English tends to use "proficient in" more frequently with skill domains, while British English sometimes favors "proficient at" for the same contexts:

American: She is proficient in calculus.
British: She is proficient at calculus.

Corpus analysis from the Corpus of Contemporary American English (COCA) and the British National Corpus (BNC) shows "proficient in" appearing approximately 30% more frequently in American sources compared to British sources for academic subjects.

However, both varieties maintain the distinction between activities ("at"), domains ("in"), and tools ("with"), even if the boundaries sometimes shift slightly.

ESL Teaching Approaches

English language instruction approaches the "proficient + preposition" question differently across regions:

European ESL curricula, influenced by the Common European Framework, typically emphasize the categorical distinctions between prepositions as described earlier.

Asian ESL programs often teach these constructions as fixed collocations to be memorized, sometimes oversimplifying the patterns.

North American ESL textbooks frequently present "proficient in" as the default construction, introducing the alternatives later as refinements.

These different teaching approaches contribute to regional variation in non-native speaker usage.

Workplace Communication Standards

Professional communication standards for "proficient" vary by industry and location:

International organizations like the UN and multinational corporations typically standardize on "proficient in" for language requirements regardless of regional location.

Technology sectors in different regions show distinct preferences:

Silicon Valley job descriptions favor "proficient with" for specific technologies
European tech firms often use "proficient in" for the same technological skills

Government documentation standards vary significantly:

US government positions typically specify "proficient in" for knowledge requirements
UK civil service often uses "proficient at" for similar contexts

Organizations with style guides usually specify preferred constructions to maintain consistency.

Prepositional Patterns With Similar Adjectives

Understanding how prepositions work with other ability-related adjectives helps reinforce the patterns seen with "proficient."

Comparing "Skilled," "Expert," and "Competent"

Skilled follows patterns similar to "proficient":

Skilled in (domains): skilled in mathematics
Skilled at (activities): skilled at problem-solving
Skilled with (tools): skilled with precision instruments

Expert shows a stronger preference for "in" across categories:

Expert in (domains): expert in constitutional law
Expert in/on (activities): expert in conducting research
Expert with (tools): expert with surgical instruments

Competent exhibits patterns similar to "proficient":

Competent in (domains): competent in business administration
Competent at (activities): competent at managing projects
Competent with (tools): competent with digital marketing platforms

These parallel patterns reinforce the semantic distinctions between prepositions.

How Preposition Choice Shifts Meaning

The same adjective paired with different prepositions creates meaningful contrasts:

Knowledgeable:

Knowledgeable in history (possesses domain knowledge)
Knowledgeable about current events (familiar with specific topics)

Experienced:

Experienced in healthcare (general field experience)
Experienced at negotiating (activity-specific experience)
Experienced with medical records systems (tool-specific experience)

Fluent:

Fluent in Spanish (overall language mastery)
Fluent at translation (activity-specific capability)

These patterns demonstrate how English consistently uses prepositions to signal different aspects of capability across various adjectives.

Teaching and Learning These Distinctions

For language learners and teachers, developing preposition mastery requires targeted approaches.

Effective Learning Strategies

Research in second language acquisition suggests several effective approaches for mastering preposition usage:

Collocation awareness: Actively noticing which prepositions commonly appear with "proficient" in authentic texts helps internalize patterns. Creating a personal collocation notebook with examples helps reinforce these observations.

Contextual learning: Rather than memorizing rules in isolation, encountering and using these constructions in meaningful contexts leads to better retention. Activities like resume writing provide practical application.

Visualization techniques: Creating mental images that represent the relationships implied by each preposition:

"At" = performing an action (visualize doing)
"In" = immersed in a field (visualize being surrounded)
"With" = using tools (visualize holding instruments)

Chunking: Learning complete phrases as units rather than separate components helps develop intuitive mastery:

"proficient in English"
"proficient at solving problems"
"proficient with Excel"

Teaching Approaches for ESL Instructors

Language teachers can employ several techniques to help students master these distinctions:

Corpus-based examples: Exposing learners to authentic usage examples drawn from language corpora builds awareness of real-world patterns.

Contrastive activities: Creating exercises that directly compare prepositional choices in parallel contexts highlights the semantic differences:

The engineer is proficient in structural analysis.
The engineer is proficient at analyzing structural problems.
The engineer is proficient with structural analysis software.

Error correction focused on meaning: When correcting preposition errors, explain how meaning shifts rather than simply marking the grammar mistake.

Task-based practice: Assigning real-world tasks like writing job applications that require appropriate preposition selection creates purposeful practice.

Assessment Considerations

When evaluating language proficiency, consider these approaches to preposition mastery:

Context-rich assessment: Test preposition knowledge in authentic contexts rather than isolated fill-in-the-blank exercises.

Production-focused evaluation: Assess learners' ability to use appropriate prepositions in their own writing and speaking rather than just recognizing correct forms.

Progressive expectations: Recognize that preposition mastery develops gradually, with initial emphasis on avoiding major errors, followed by developing nuanced understanding of semantic distinctions.

Digital Communication and Changing Usage Patterns

Language evolves constantly, and digital communication influences preposition usage with "proficient."

Impact of Resume Scanning Software

Automated applicant tracking systems (ATS) have influenced how job seekers phrase their skills:

Keyword optimization has led many to default to the most common construction—"proficient in"—regardless of whether it's semantically optimal, because data shows this form appears most frequently in job descriptions.

A 2023 analysis of ATS data revealed that 72% of resumes now use "proficient in" as the default construction, even for tool-related skills that traditionally paired with "proficient with."

This trend risks flattening the meaningful distinctions discussed throughout this article.

Social Media and Professional Profiles

Professional networking platforms have developed their own conventions:

LinkedIn profiles show a strong preference for "proficient in" across all categories, likely influenced by the platform's structured skills sections.

Industry-specific platforms maintain more traditional distinctions:

Developer communities (GitHub, Stack Overflow) preserve the "proficient with" construction for technologies
Creative portfolios typically maintain "proficient at" for performance skills

Contemporary Trends in Usage

Analysis of recent corpus data reveals several emerging patterns:

Simplification trend: Younger professionals increasingly default to "proficient in" across most contexts, potentially reducing the semantic precision of traditional usage.

Industry resistance: Technical fields maintain stronger distinctions between prepositions, seeing them as meaningful indicators of different types of capability.

International standardization: Global business communication increasingly standardizes on "proficient in" for simplicity in cross-cultural contexts.

Academic preservation: Scholarly and educational contexts continue to maintain traditional prepositional distinctions as markers of precise language.

Practical Applications and Takeaways

Having explored the nuances of preposition use with "proficient," let's crystallize the key insights into practical guidance.

Decision Framework for Choosing the Right Preposition

When deciding which preposition to use with "proficient," ask yourself these questions:

What type of proficiency am I describing?
Knowledge of a subject area → "proficient in"
Performance of an activity → "proficient at"
Use of tools or instruments → "proficient with"

2. What aspect do I want to emphasize?

Theoretical understanding → "proficient in"
Practical execution → "proficient at"
Instrumental application → "proficient with"

3. What's the conventional usage in my specific context?

Consider industry standards and regional norms
Check similar examples in your field

This framework provides a structured approach to making appropriate preposition choices.

Key Points to Remember

To master the use of prepositions with "proficient," keep these core principles in mind:

Semantic logic: The preposition choice reflects the relationship between the person and what they're proficient in/at/with.
Context sensitivity: While general patterns exist, context sometimes allows flexibility based on the aspect of proficiency being emphasized.
Evolution awareness: Usage patterns evolve over time, with some contexts becoming more standardized while others maintain traditional distinctions.
Communication purpose: The ultimate goal is clear communication—choose the preposition that most precisely conveys your intended meaning.

Building Language Precision

Developing precision with prepositions requires deliberate attention:

Active observation: Notice preposition patterns in professional writing in your field.
Contextual practice: Apply these distinctions in your own communication with awareness of their implications.
Feedback integration: Be open to guidance from editors or language experts about conventional usage in specific contexts.
Balance preservation with evolution: Understand traditional patterns while recognizing when usage norms are shifting.

Learn Any Language with Kylian AI

Private language lessons are expensive. Paying between 15 and 50 euros per lesson isn’t realistic for most people—especially when dozens of sessions are needed to see real progress.

Many learners give up on language learning due to these high costs, missing out on valuable professional and personal opportunities.

That’s why we created Kylian: to make language learning accessible to everyone and help people master a foreign language without breaking the bank.

To get started, just tell Kylian which language you want to learn and what your native language is

Tired of teachers who don’t understand your specific struggles as a French speaker? Kylian’s advantage lies in its ability to teach any language using your native tongue as the foundation.

Unlike generic apps that offer the same content to everyone, Kylian explains concepts in your native language (French) and switches to the target language when necessary—perfectly adapting to your level and needs.

This personalization removes the frustration and confusion that are so common in traditional language learning.

Choose a specific topic you want to learn

Frustrated by language lessons that never cover exactly what you need? Kylian can teach you any aspect of a language—from pronunciation to advanced grammar—by focusing on your specific goals.

Avoid vague requests like “How can I improve my accent?” and be precise: “How do I pronounce the R like a native English speaker?” or “How do I conjugate the verb ‘to be’ in the present tense?”

With Kylian, you’ll never again pay for irrelevant content or feel embarrassed asking “too basic” questions to a teacher. Your learning plan is entirely personalized.

Once you’ve chosen your topic, just hit the “Generate a Lesson” button, and within seconds, you’ll get a lesson designed exclusively for you.

Join the room to begin your lesson

The session feels like a one-on-one language class with a human tutor—but without the high price or time constraints.

In a 25-minute lesson, Kylian teaches exactly what you need to know about your chosen topic: the nuances that textbooks never explain, key cultural differences between French and your target language, grammar rules, and much more.

Ever felt frustrated trying to keep up with a native-speaking teacher, or embarrassed to ask for something to be repeated? With Kylian, that problem disappears. It switches intelligently between French and the target language depending on your level, helping you understand every concept at your own pace.

During the lesson, Kylian uses role-plays, real-life examples, and adapts to your learning style. Didn’t understand something? No problem—you can pause Kylian anytime to ask for clarification, without fear of being judged.

Ask all the questions you want, repeat sections if needed, and customize your learning experience in ways traditional teachers and generic apps simply can’t match.

With 24/7 access at a fraction of the cost of private lessons, Kylian removes all the barriers that have kept you from mastering the language you’ve always wanted to learn.

Take your free lesson with Kylian today.