key
A1All registers (highly common)
Definition
Meaning
A small piece of shaped metal used to open or close a lock.
Anything that provides access, understanding, control, or success; a crucial or essential element.
Linguistics
Semantic Notes
A polysemous word with concrete (physical key) and abstract (key to success) meanings that are deeply connected. Its adjectival use ('key player') is a classic example of functional shift.
Dialectal Variation
British vs American Usage
Differences
In computing, 'key' is standard for both. In music, the 'piano key' is identical. In American football, the 'key' is used strategically to read plays. Minimal differences, primarily in specific collocations or jargon.
Connotations
Both share core connotations of access, control, and essentiality. 'Key' can have a slightly stronger connotation of 'fundamental' in academic/technical contexts.
Frequency
Extremely high frequency in both varieties. The adjectival use ('key factor') is slightly more frequent in formal/business contexts globally.
Vocabulary
Collocations
Grammar
Valency Patterns
key to + noun (the key to the door)key to + -ing form (the key to understanding)key + noun (key issue)verb + key (turn the key, press a key)Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “keyed up (nervous)”
- “under lock and key”
- “the key to someone's heart”
- “hold the key to”
Usage
Context Usage
Business
Refers to critical success factors, important clients (key account), or strategic personnel.
Academic
Used for fundamental concepts, main arguments, or critical evidence.
Everyday
Primarily refers to physical keys for doors/cars and metaphorical access (key to happiness).
Technical
In computing: a button on a keyboard or a field in a database. In music: a tonal centre. In mechanics: a tool for winding or turning.
Examples
By Part of Speech
verb
British English
- She carefully keyed in the security code.
- The vandal keyed a deep scratch along the car door.
American English
- He keyed the microphone before speaking.
- The player keyed on the opponent's weak foot.
Examples
By CEFR Level
- I can't find my house key.
- The teacher gave us the key to the exercise.
- Confidence is often the key to a successful interview.
- Remember to press the 'enter' key.
- The researcher identified a key flaw in the experiment's methodology.
- He was a key figure in the negotiations.
- The essay's key contention rests on a disputed interpretation of the primary sources.
- Their defence was strategically keyed to counter the opponent's aerial attack.
Learning
Memory Aids
Mnemonic
Imagine a large, old-fashioned KEY. The top part (the bow) looks like a question mark (?). A KEY is the answer (the thing that unlocks the question).
Conceptual Metaphor
IMPORTANT IS CENTRAL / ACCESS IS A KEY. Ideas are often conceptualised as locks that require keys (understanding) to open.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating 'key role' as 'ключевая роль' in every context—'crucial role' or 'vital role' might be more natural. The musical 'key' (тональность) is a different concept from a piano 'key' (клавиша). The computing 'key' is клавиша, not ключ.
Common Mistakes
- Using 'key' as an adjective without a noun ('This is very key' – informal/incorrect in formal writing). Confusing 'key to' with 'key for' (generally, 'key to' is correct for abstract meanings).
Practice
Quiz
In which sentence is 'key' used as a verb?
FAQ
Frequently Asked Questions
In formal writing, no. Use 'crucial', 'essential', or 'very important'. 'Very key' is considered informal or colloquial.
'Key to' is far more common, especially with abstract nouns (key to success). 'Key for' is sometimes used when referring to a specific purpose or person (a key for the back door, this information is key for her).
As an adjective, it means 'of crucial importance'. It cannot replace 'important' in contexts where the meaning is simply 'significant' but not fundamental (e.g., 'an important email' not 'a key email').
It's an idiom meaning nervous, excited, or tense, often before an important event (e.g., 'The team was keyed up before the final match').
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