let's

Let us / Let's + infinitive

Let us and its contraction let’s are used to make offers, proposals, or suggestions in a friendly and inclusive way. They mean “you and I should …” or “we should …”. The contraction let’s is far more common in everyday English.

Form

• Affirmative: Let us / Let’s + base form of the verb
  Let’s go. (Let’s you-and-I go.)
• Negative: Let us not / Let’s not + base form of the verb
  Let’s not hurry. (Let’s you-and-I avoid hurrying.)

Use

We use let us / let’s to suggest an action that the speaker and the listener will do together. It sounds polite, cooperative, and inviting.

Examples

Let’s try this new restaurant. (We should try it.)
Let’s not waste time. (We should avoid wasting time.)
Let us begin the meeting. (A more formal way to say we should start.)
Let us not forget our goals. (A formal suggestion to avoid forgetting.)

Notes

Let us (uncontracted) is more formal and common in speeches, ceremonies, or written instructions. Let’s is natural in everyday conversation.