Let vs. Leave
Let and leave are not interchangeable general synonyms. Let commonly expresses permission and takes an object plus a bare infinitive; leave has several separate senses involving departure, omission, remaining, and some permission-like constructions.
Use “let” when you mean allow or permit: “Let her speak.” Use “leave” for departing, not taking something with you, or allowing something to remain: “Leave the box here.” Their grammar patterns and meanings overlap only in limited constructions.
Key details
Choose the right form
| Meaning / context | Use | Decision |
|---|---|---|
| allow someone to do something | let + object + bare infinitive | “Let me explain,” not “let me to explain.” |
| go away from a place or person | leave | Use the departure sense. |
| allow something to remain in a state/place | leave | Use constructions such as “leave the door open” or “leave it there.” |
Quick tests
Decision test
Does the sentence mean “allow someone to do an action”?
If yes: Use “let” with the person/thing followed by the base verb.
If no: Use “leave” when the meaning is depart, not take, or allow something to remain; check the specific complement pattern.
Caveat: Do not replace every “leave” construction with “let.” The verbs have different senses and complementation patterns.
Examples
Let the students choose their own examples.
“Let” expresses permission and takes the object plus base verb “choose.”
Please leave the keys on the desk.
“Leave” means allow the keys to remain in that place.
She left the office before noon.
This is the departure sense of “leave,” with no “let” counterpart.
Further guidance
Core difference
“Let me explain,” not “let me to explain.”
Fast Test
Use “let” with the person/thing followed by the base verb. Use “leave” when the meaning is depart, not take, or allow something to remain; check the specific complement pattern.
Usage Boundary
Do not replace every “leave” construction with “let.” The verbs have different senses and complementation patterns.
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.
- Word choice: let or leave? (opens in a new tab)Cambridge University Press · Cambridge directly distinguishes let for allowing someone to do something from leave for going away or not taking someone or something with you.
- leave (opens in a new tab)Cambridge University Press · Leave has multiple movement, departure, remaining, and permission-related constructions that must not be collapsed into the causative/permission verb let.