"Are we going to drink?"
Translation:Allons-nous boire ?
Be carefull ! "va t'on" does not exist ; it is "va-t-on"
the t' is the pronoun "toi" (tu as a COD) before a vowel . For example "je t'aime" (i love you) = je aime toi . However "je aime toi" is not correct ; to get the correct structure you have to put "toi" before the verb
In the sentence "Va-t-on boire ?" ; the -t- is use to link the verb with the pronoun when we pronounce the sentence.
You may have notice that the french language often links words with each other, we call it "liaison" . There is a liaison when a word ends with a consonnant and the next one starts with a vowel . For example "Nous allons à la campagne" will be pronouced [nou-z-allon (-z-) à la campagne]. (we are going to the countryside) I put the second liaison between () because it is ok to skip it
So -t- in "va-t-on boire" is use to make a liaison between the verb "va" and the pronoun "on"