Let

We can use let to mean to rent out a house.

• We moved to Australia and let our house in London.

A major use of let is for talking about ‘allowing’ and ‘permission’.

• My mother let me come.
• I let her leave early.

One pattern is let followed by an OBJECT followed by a BARE INFINITIVE

• She let me have the last one.
• You must let us know when you are coming to New York.
• I didn’t let my friend drive my car.
• Why did you let Jane do that?

Another pattern is let followed by an OBJECT followed by a COMPLEMENT

• Let me past.
• The police aren’t letting anybody out of the building.
• Don’t let him get away.
• Why did you let him in?

Notice that we can use reflexive pronouns to talk about what we allow ourselves to do.

• I let myself be influenced by her.
• She let herself out.
• I didn’t let myself be talked into it.
• Did you let yourself in?

Notice that we do not make a contraction out of let us when asking for permission.

• Let us help you.
• Let us pay for this.
• Let us buy that.
• Let us take the risk.

We use let’s when we are making a suggestion.

• Let’s go to the cinema.
• Let’s stay at home.
• Let’s not argue. (formal)
• Don’t let’s argue. (informal)

Compare these

• Let us watch TV, please. (asking for permission)
• Let’s watch TV. (a suggestion)

There are many fixed expressions, idioms and phrasal verbs using let.
Let alone means ‘much less’

• I’ve never been to Africa, let alone Ghana.
• I’ve never met any actor, let alone Brad Pitt.

Let go can mean to dismiss

• My company let 20 people go.
• I was let go three weeks ago.

Let your hair down means to lose your inhibitions.

• At the office party, everybody let their hair down and we had fun.

Don’t let it get you down means to stay cheerful although something bad has happened.

• Everybody makes mistakes. Don’t let it get you down.

Let you off/let you off the hook means that you are excused, even though you did something wrong or had something bad to do.

• I made a mess but the boss let me off.
• I was supposed to tidy up after the party but I was let off the hook as Sandra did it.

Letting off steam means to get rid of excess energy or frustration.

• After work I go to the gym and let off steam on the treadmill.
• We need to go out after the exams and let off steam.

Let me see and let me think are expressions used to give you time to think.

• You want a raise? Let me think. Can we discuss this later?
• A good place for lunch? Let me see. How about the Italian restaurant?

Let’s say and let’s suppose are used to talk about hypothetical situations.

• Let’s say that you were boss. What would you do?
• Let’s suppose that we don’t get the contract. What do we do?

Let’s hope is used to express a hope.

• Let’s hope he gets the job.
• Yes, let’s hope so.