Proficient In: Standard Pattern
Proficient In: Standard Pattern records the directly documented Cambridge construction and keeps the guidance bounded to the evidenced complement pattern rather than inventing a broader prohibition.
Cambridge documents “proficient in” for skill in a language, technology, field, or similar domain.
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| skill in a language, technology, field, or domain | proficient in + noun/domain | Use the documented “in” construction. |
| skill at performing an activity | proficient at + activity | Cambridge also documents “at” in activity contexts. |
| choose a preposition without checking what follows | match the complement to the intended construction | Do not turn this page into a claim that only “in” can ever follow “proficient.” |
Quick tests
Meaning / construction test
Does the complement name a field, language, technology, or similar domain of skill?
If yes: Use “proficient in.”
If no: If the complement is an activity, “proficient at” is also documented and may fit better.
Caveat: This page records the “proficient in” construction but does not exclude the separately documented “proficient at” pattern for activities.
Examples
She is proficient in Spanish.
The complement names a language, so “in” fits the documented pattern.
He is proficient in spreadsheet software.
The complement names a technology/domain of skill.
She is proficient at repairing small engines.
Cambridge also documents “at” when the complement is an activity.
Further guidance
Construction
Cambridge documents proficient in for skill or experience in a language, technology, field, or similar domain, while also documenting proficient at for activities.
Style Boundary
This page records the evidenced proficient-in construction while noting that Cambridge also documents proficient at in other complement contexts.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- proficient — Cambridge Dictionary (opens in a new tab)Cambridge University Press · Cambridge dictionary evidence for proficient in a language, field, or technology.