Let's... and Why don't we...? for making suggestions to friends.

Let's - for making suggestions and Why don't we …….Both constructions are followed by the verb. No change to the verb.

e.g. Girl: Let's go to the cinema tonight. There's a good film on.
Boy: Let's not. I'd rather stay in and watch TV. Let's have a take-away and watch the football.
Girl: I hate football. I don't want to stay at home and watch TV. It's boring.
Boy: Why don't you ring some of your girlfriends and go out together.
Girl: Because I want to do something with you.

n.b. "Let's" includes the speaker and the person or people (s)he is speaking to. It's a contraction for "let us" plus the verb. "Why don't we…" acts in the same way. They are both friendly suggestions used in conversation.

Practice Exercise:
1. … go to the zoo. I like watching the monkeys and apes.
2. I'd rather not. I don't like zoos. ……(not) go out. …..stay at home.
3. Tell you what! …….. you stay at home and I'll go out!
4. That's no fun. I want to do something together.
5. All right. …….go down the pub.
6. All right.

Answer:
1. Let's go to the zoo - why don't we go to the zoo? I like watching the monkeys and the apes.
2. Let's not go out. (n.b. It's negative.) Let's stay at home.
3. Tell you what! Why don't you stay at home and I'll go out!
4. That's no fun. I want to do something together.
5. All right. Let's go to the pub.
6. All right.

Read The A - z of English Grammar & Usage to see the rules.

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