Asking questions using inversion (2)

When forming a question using the perfect tense, it is the auxiliary verb that is inverted with the subject :

Avez-vous reçu ma lettre?

Did you receive my letter?

As-tu acheté du pain?

Did you buy some bread?

Where the subject is il or elle and the verb ends in a vowel , -t- is added. This is to make it sound better:

A-t-elle aimé le film?

Did she like the film?

A-t-il lu le livre?

Did he read the book?