There's no difference. Neither occurs in a sentence tag.What's the difference between "let's" and "let us" in question tag?
There's no difference between 'Let's' and 'Let us'.I mean when we say "will you?" at the end of the sentence and when we say "Shall we?".
Someone who uses 'shall' can answer this part.
Ex: Let's go somewhere different tonight, shall we? (What if we change the first part into: Let us?)
Please dad, let me and him go to the cinema, ..... ? (What do you choose? Will you or shall we?
Yes, I should have clarified this. "Let us" does not always mean "Let's", as others have pointed out.When we learn English in our country, we're told that "let's" is different from "let us". If one says "let's do something", that means the speaker involves the listener in the activity, so we are told to use "shall we?" ;if "let us do something", it means the speaker doesn't involve the listener in the activity, so we are told to use "will you?". Does such a "theory" not exist at all actually?