I read this part in a book:

I wonder if this is correct because I always form such sentence like the English "Let's ..." with "lassen" ("lass uns ..."), for example:
Lass uns gehen
Lass uns sehen
Lass uns hier setzen
So:
- Which one is correct or more common?
- While searching for the answer in Google, I saw also "Lasst ...", is it another form of "let's ..."?
Lass uns hier setzen, sondern entwederLass uns hier sitzenoderLass uns uns hier hinsetzen. – user unknown Nov 30 '11 at 16:33