Breakdown of A che ora la lasci tornare stasera?
che
what
tornare
to return
a
to / at
stasera
tonight / this evening
Questions & Answers about A che ora la lasci tornare stasera?
Why do we use the direct object pronoun la here instead of the indirect object pronoun le?
In the lasciare + infinitive structure, the person you let do something is the direct object (la) if the second verb doesn't take an object of its own (like tornare, which is intransitive). If she were doing an action to something else, like eating a pizza, she would become the indirect object (le).
Can I attach the pronoun la to the end of the infinitive, saying lasci tornarla?
Could I use permettere instead of lasciare to say 'let' or 'allow'?
Yes, but the grammar would change. Permettere requires an indirect object and the preposition di. The sentence would become A che ora le permetti di tornare stasera? Lasciare is much more common in everyday speech because the structure is simpler.
Why is it A che ora and not just Che ora?