"Let's go" in Spanish: vayamos vs vamos vs vámonos

Question

I understand that "Let's go" in Spanish is vámonos or vamos depending on the context.

However, I have also learned from grammar books that all the "let's..." constructs translate into Spanish using the 1st person plural subjunctive conjugation.

That's how we get platiquemos (from platicar) for "let's talk" and andemos (from andar) for "let's walk."

By that analogy, shouldn't "let's go" translate into vayamos? Even the first person plural imperative of ir is vayamos.

Why do we use vamos then?

Answer 1

I'm a native speaker, and I have never realized this strange anomaly.

I've found a possible explanation for this difference in the conjugation of the Spanish verb ir, given by the Diccionario Panhispánico de Dudas (boldened text by my own):

2. La forma vamos es hoy la primera persona del plural del presente de indicativo: «Laureano y yo nos vamos al jardín» (Gallego Adelaida [Esp. 1990]); pero en el español medieval y clásico era, alternando con vayamos, forma de primera persona del plural del presente de subjuntivo: «Si vos queréys que vamos juntos, pongámoslo, luego, por obra» (Daza Antojos [Esp. 1623]). Como resto de su antiguo valor de subjuntivo, la forma vamos se emplea, con más frecuencia que vayamos, con finalidad exhortativa: «Vamos, Johnny, vamos a casa que es tarde» (Cortázar Reunión [Arg. 1983]); la forma de subjuntivo vayamos, con este sentido, ha quedado casi relegada a la lengua literaria: «Vayámonos de aquí» (Amestoy Durango [Esp. 1989]). Lo que no debe hacerse en ningún caso es emplear hoy la forma vamos, en lugar de vayamos, en contextos que exigen subjuntivo y sin que exista, en el enunciado, intención exhortativa: «Tenemos una excelente relación [...]. Pero no es que vamos juntos para el cine» (Universal [Ven.] 3.9.96); debió decirse no es que vayamos.

So:

• vamos was in medieval Spanish another form for first person plural of present of subjunctive.
  • that is to say: both vamos and vayamos were used in that case.
  • vamos was also used (as well as today) as first person plural of present of indicative.
• nowadays, the only "vestige" of that old use for vamos is the fact that it is also used as imperative plural for the first person.

Answer 2

Preliminary remark: Some other verbs can follow this path, in some contexts. For example, let's say my family and I are sitting down to eat, but we get involved in a heated discussion and the food gets forgotten. I can exhort or invite everyone to start eating, and continue the discussion calmly. There are several ways of doing this.

Comamos [subjunctive... imperative]

Vamos a comer [sort of future... sort of another type of imperative]

Comemos [present indicative... a suggestion]

The third approach might be clearer if I write it like this:

Comemos, ¿no? ¿Y seguimos discutiendo, pero con calma?

Now, to answer your question, the main reason we use "vámonos" instead of "vayámonos" typically is that it flows better in the context -- which generally calls for something short and punchy.

However, there are situations in which "vayamos" can be comfortably used. Examples:

Vayamos al tema de la investigación con células madre. | Let me turn to the issue of stem cell research. (Example taken from linguee.com)

No hay que quedarse con el estatu quo. Vayamos avanzando con nuestras metas. | We shouldn't stay stuck with the status quo. Let us move forward with our goals.

No nos vayamos todavía. Quiero quedarme otro rato. | Don't let's go yet. I want to stay a little longer.