Key vs Major

When to use each in English, with meaning, register, and examples.

	Key	Major
Meaning	A small metal thing that you use to open a lock.	Very important or large.
CEFR level	A1	A2
Part of speech	noun	adjective
Usage notes	Use 'key' when talking about unlocking doors or starting cars. Avoid using it in overly formal contexts unless referring to 'key concepts' or 'key players'.	Use 'major' to describe something significant in formal and everyday contexts, but avoid it in highly casual situations.

Frequently asked questions: Key vs Major

What's the difference between "Key" and "Major"?

"Key" means: A small metal thing that you use to open a lock. "Major" means: Very important or large.

When should I use "Key" and "Major"?

They can all be used in everyday English.

Are "Key" and "Major" the same CEFR level?

"Key" is at A1, "Major" is at A2 on the CEFR scale.