Quick answer: Leave = go away from a place, or allow something to remain in a particular state: Leave the door open. Let = allow or permit someone to do something: Let me explain. The most common confusion is using let instead of leave with objects. For a fuller definition, see the Cambridge Dictionary entry for ‘leave’.
Comparison Table
| Word | Part of Speech | Meaning | Example |
|---|---|---|---|
| leave | verb | go away from; allow to remain in a state | Leave the door open. / She left early. |
| let | verb | allow or permit someone to do something | Let me explain. / Let the children play. |
Using Leave — Departing and Leaving Things in a State
Leave has two main meanings. First, it means to go away from a place or person: you leave the office, leave a party, leave someone behind. Second, it means to allow something to remain in a particular state or position: you leave the window open, leave the engine running, leave a note on the table. In both uses, the key idea is that you move away or allow something to stay as it is without intervening further.
She left the office at six o’clock.
Please leave your bags at reception.
Leave the window open — it’s hot.
He left a message on the answerphone.
Leave + Object + Adjective or Participle
One of the most important patterns with leave is leave + object + adjective or past participle. This means to allow something to remain in a particular condition: leave the door open, leave it untouched, leave the engine running, leave the question unanswered. This construction is very common in English and is frequently confused with let by learners. Remember: if you are describing the state something is left in, use leave.
She left the tap running all night.
He left his lunch untouched.
Don’t leave the computer on overnight.
They left the decision unmade.
Using Let — Permission and Allowing
Let means to allow or permit someone to do something. It is always followed by an object + bare infinitive (an infinitive without to). The person or thing being allowed must always be present in the sentence: let me know, let them go, let the children play outside. If you want to express that you are granting permission for an action to happen, let is the correct verb to reach for.
Let me help you with that.
His parents let him stay up late on weekends.
Let the dough rest for an hour.
Let me know when you arrive.
Let + Object + Bare Infinitive
The grammar rule for let is strict: let + object + bare infinitive — never to + infinitive. “Let me go” is correct; “Let me to go” is wrong. This is one of the most common errors learners make. Beyond the basic pattern, let appears in several important idioms: let it go (allow something to end or stop caring about it), let someone down (disappoint them), and let someone in/out (allow entry or exit).
Let the water cool before drinking it.
She let him borrow her car.
Don’t let the dog out!
Side by Side: Leave vs Let
Seeing the two verbs used in parallel contexts makes the distinction much clearer. The words often feel interchangeable to learners, but the grammar and meaning are distinct.
Leave him alone. — (don’t disturb him; go away or stop bothering him)
Let him be. — (allow him to exist as he is — also acceptable, but less common than leave alone)
Leave the bag here. — (put the bag down and go away from it)
Let me carry the bag. — (give me permission to carry it)
Common Mistakes
✗ Let the keys on the table.
✓ Leave the keys on the table.
Note: Let requires a person + bare infinitive, not just an object placed in a location. When you are talking about putting something somewhere and going away, use leave.
✗ She leaved me go early.
✓ She let me go early.
Note: Let is an irregular verb — its past tense is also let, not leaved. “Leaved” does not exist as a past tense form of leave (the correct past tense of leave is left).
✗ Leave me to explain. — (sounds as though you want to depart from someone)
✓ Let me explain.
Note: When asking for permission to perform an action, let is the correct verb. Leave me to + infinitive suggests going away from someone so you can do something in private, which is a very different meaning.
Also confusing: Affect vs Effect, Advice vs Advise, Lay vs Lie, Look vs Seem. Browse all confusing word pairs →
Quick Check: Leave or Let?
Four questions — choose the correct word for each sentence.
1. “___ me help you with that.”
2. “She decided to ___ her job and move abroad.”
3. “Please ___ the door open.”
4. “His parents ___ him stay up late.”
Frequently Asked Questions
What is the difference between leave and let?
Leave means (1) to go away from a place or person, or (2) to allow something to remain in a particular state: “Leave the door open,” “She left early.” Let means to allow or permit someone to do something, and is followed by object + bare infinitive: “Let me explain,” “Let the children play.” The most common confusion is using let instead of leave when placing an object somewhere.
Can “leave” mean “allow”?
Yes, in the pattern leave + object + adjective/participle, leave does mean allow something to remain in a state: “Leave the window open” means allow the window to remain open. However, this is different from let + object + infinitive, which expresses permission to perform an action: “Let him speak.” Both involve allowing, but the grammar and meaning are distinct.
What is the structure of “let” in English?
Let is followed by an object + bare infinitive (without “to”): “Let me go,” “Let them decide,” “Let the water cool.” Never use “to” after let: “Let me to go” is incorrect. The past tense of let is also let (irregular): “She let me borrow her notes.” It does not add -ed: “letted” does not exist.
What is the difference between “leave alone” and “let alone”?
“Leave someone alone” means to stop bothering them or to go away from them: “Leave me alone! I’m trying to work.” “Let alone” is a completely different phrase meaning “much less” or “not to mention”: “I can’t afford a holiday, let alone a trip abroad.” “Leave alone” and “let alone” are not interchangeable — they have entirely different meanings.
Is “leaved” a word?
No. The past tense of leave is left (irregular): “She left early,” “He left the keys on the table.” “Leaved” is not standard English. Note that trees can be described as “leaved” as an adjective (meaning having leaves), but this is unrelated to the verb leave meaning to depart.
What does “let it go” mean?
“Let it go” means to stop worrying about or holding onto something — to release it mentally or emotionally: “I know you’re upset, but you need to let it go.” It is an extremely common idiom in English. The literal meaning is to release something you are holding. Note the grammar: let + it + go (bare infinitive, no “to”).
How do you use “leave” with time expressions?
Leave is commonly used with time expressions when talking about departure: “She left at noon,” “The train leaves in five minutes,” “We’re leaving tomorrow morning.” Also common: “leave early,” “leave on time,” “leave late.” Note the difference: “I left” (past, already gone) vs “I’m leaving” (present progressive, about to go).
What are common collocations with “let”?
Common collocations: let me know (inform me), let someone down (disappoint), let someone in/out (allow entry or exit), let go of something (release), let it slide (overlook), let off steam (release tension), let someone off (excuse from punishment). Also common structures: let’s (let us — suggestion): “Let’s go!” and “Don’t let...” for warnings: “Don’t let the fire go out.”
When do native speakers use “let” vs “allow”?
Let and allow are often interchangeable but have slightly different registers. Let is more informal and direct: “Let me in!” Allow is more formal: “Passengers are not allowed to use mobile phones.” The grammar also differs: let + object + bare infinitive (“let me go”) vs allow + object + to-infinitive (“allow me to go”). In everyday speech, let is far more common.
Can “leave” and “let” appear in the same sentence?
Yes: “Leave the key under the mat and let the cleaner in.” Here leave means to place and go, and let means to allow entry. Another natural example: “She decided to leave her job and let someone else take over.” Both words in one sentence shows strong command of English verb usage.