Translation of ”Let’s go there together tomorrow"

Question

Since the paragraph was using 'on' consistently, I chose "On y va ..." instead of "Allons-y ...".  Why is this wrong?

Accepted Answer

Bonjour Frank,
Chris is right! Also, "On y va !" is in Le Présent Indicatif whereas "Allons-y !" is in L'Impératif.
Take a look here at a similar query here: Difference between "On y va!" and "Allons-y!"
I hope this is helpful.
Bonne journée !

Answer

Salut Frank,It is a question of immediacy is it not? (Although both are in the impératif mood)If we write "On y va .." the sense is of "let's go" but short term ie. Now or very soon.But if we write "Allons-y".  Here the sense is potentially not immediately / now; but more further out in the future and the text of the lesson supports this particular and (perhaps) more formal sense of immediacy (ie. tomorrow).Hope this helps.Bonne journéeJim

Answer

Both are very close in meaning, although there's a slight difference:
allons-y -- a bit more formal and emphasises the destination "there": let's go there"on y va -- familiar register, is often used to mean "let's go!" without emphasis of where to go.

Answer

I put Va-t-on! Is that wrong?

Answer

Bonjour CHarles,
"Va-t-on" is not a translation of "Let's go". It is what you would use to ask a question (specifically an inverted question):
Va-t-on au cinéma ce soir ? = Are we going to the cinema tonight?
Take a look here: 
Inverted questions in the present tense (Le Présent) in French - il/elle/on forms
Conjugate regular verbs in the imperative mood in French (L'Impératif)
I hope this is helpful.
Bonne journée !