The Differences with "Let".
What is the difference between between "dejar" which means "Let's" and the set phrase "Vamos a +infinitive" which also means "Let's". When would I expect to see one being used rather than the other?
eg.
Vamos a ver
Vamos a empezar
Thank you.
4 Answers
"dejar" is used for "to let someone do something". "vamos" is used for "let us"
Expanding on fidalgo's perfectly correct answer, dejar means to allow, permit, leave, (or leave off), or stop doing something. So when 'let' means allow, use dejar.
Let's in English sometimes expresses a first-person plural command. "Let's go to the movies." "Let's have pizza." "Let us pray." On these occasions you could use "vamos a".
The fancy term (especially if one is studying Latin) for "let's ..." is the "hortatory subjunctive". That is to say, it is an exhortation (another fairly fancy word) to do something. In other words, an encouragement/invitation to (some) action. As such, it really only applies to the 1st person plural. "Let's go." / "Let's have pizza." / "Let's play charades."
When 'let' means allow/permit (Moses' "Let my people go.", for example), he is not saying "OK, people, we should leave this place." but, rather, (addressing himself to Pharaoh), "Allow/permit us to go". Note that in (somewhat old-fashioned English) one could say "give us your leave" which approaches some other translations of 'dejar' (e.g. to leave behind / dejar atrás).
I'll say nothing of 'let', as in 'rooms to let', since that does not appear to be a source of confusion.
The "vamos a" form is used for commands or suggestions, like "Let's eat pizza." The "dejar" form means to allow, permit or leave so you should only use this for commands like "Let us be." Hope that helps!
