May I know why is this use vosotros instead ustedes?

Question

I'm taking this question from the quiz. Why is this question is not for ustedes but vosotros since there are two person.Julián y tú ____quereis____ viajar por todo el mundo.

Answer

Hola CathyIf the subject is more than one person, this is a "you plural", therefore the verb needs to be conjugated in the "vosotros" form if it is considered an "informal you plural" or conjugated in the "ustedes" form if it is considered a "formal you plural".  In this case, the subject is "Julián y tú..." (Julián and you informal), so this needs to be conjugated in the vosotros form: "queréis". If the subject was this instead: "Julián y usted..." (Julián and you formal), then this would be the same as saying "ustedes" and the verb would be "quieren".Vosotros queréis..Ustedes quieren...Both referring to a you plural but one informal the other formal.I hope this clarified it.Saludos,InmaWhen the speaker is referring to