The verb avoir is irregular in the present tense.
Pronunciation note: Listen carefully and imitate the liaison between the plural subject pronouns nous, vous, ils and elles, and the verb forms. The -s is pronounced as a /z/. This liaison is a required one because of the normally silent s at the end of the subject pronoun and the verb form that begins with a vowel. We always link the two words, i.e. make a liaison, is this context; there will always be a liaison between the plural subject pronouns and verbs forms that begin with a vowel. Don't worry about this but imitate it as you listen and repeat the verb forms and it will become a habit.
Exercise: Mettez la forme du verbe avoir relatif au sujet de la phrase. Mettez j' au lieu de je.
Quel âge ________________ Caroline?
Vous ________________ une bicyclette?
Nous ________________ trois enfants.
Je ________________ 31 ans.
Tu ________________ un ordinateur?
Robert et Jean ________________ des bureaux?
Alexandre ________________ une grande fenêtre chez lui!
SUU ________________ un beau campus.