"What would you like, girls?"
Translation:Quid velitis, puellae?
For 'girls' (plural):
puellae is the nominative (the subject, the one doing the action) or the vocative plural (the person being directly addressed, which is how it is here). This form also is used as for the genitive and dative singular.
puellas is the accusative plural (used as the direct object for verbs, the thing althea verb action is being done to).