This is the 6931st most frequent Catalan word.
vau
"Vau" is the second-person plural form of the past tense of "anar" (you [plural] went).
In this sentence, 'vau' is the second person plural form of the verb 'anar' in the past tense ('preterite'), used to indicate an action performed by 'vosaltres' ('you all').
Ahir a la nit, vau anar al concert?
Last night, did you go to the concert?
Here, 'vau' serves a similar role, as a second person plural auxiliary verb used in past contexts, accompanying the past participle 'veure' ('watched').
Vau veure la pel·lícula nova de ciència-ficció que recomanen?
Did you watch the new science-fiction movie they are recommending?
In this context, 'vau' provides the past tense form of 'estudiar' when referring to actions the second person plural subject 'vosaltres' undertook.