What are the differences between "vamos" and "vámonos"?
What are the differences between "vamos" and "vámonos"?
Doesn´t it mean "Let's go!"?
5 Answers
Vamos and Vámonos should be compared to Ir and Irse.
Vamos has the meaning Let's go (to a destination) while Vámonos is more Let's leave (this place).
Ir is the only verb used in the indicative mood to form an affirmative nosotros command.
¡Vámonos! Let's leave/beat it/get out of here!
¡No nos vayamos! Let's not leave.
otro
One exception to the above rule is the verb ir, whose subjunctive form is used only for the negative nosotros/nosotras command. The affirmative nosotros/nosotras command is the indicative form: vamos.
otro
Ir is an exception. You just say “vamos.” You don’t change it to the subjunctive.
As Quentin mentioned it's the difference between ir and irse: 
'vamos' - let's go
and
'vamos nos' which drops the middle 's' and gets condensed to vámonos - let's take off/get out of here etc
It's also used as an invitation, like in: "Vamonos de pesca" (Let's go fishing) or "vamonos a comer" (let's go eat) or as in plural: (Let's all go eat.) and it's used when the action is taking place, let's say you are actually leaving to eat and some one ask you (Are you leaving ?) "ya te vas?" and you answer: (Yes, let's go eat) "si vamonos a comer" you are inviting.
Vamos is used differently than Vamonos, although you can say "Vamos a casa" and "Vamonos a casa" using both words meaning the same, when you say "Vamonos" as in "Let's go" you cannot say "Vamos" for the same thing. It's less common to say "Vamos", but they mean the same, the variation is just for specific sentences.
So, Vamonos? = Let's go?
Vamos doesn't mean let's go?
