Learn Italian: Mio cugino è diventato ricco.

In Italian, the past tense (passato prossimo) uses the helper verb essere (to be) instead of avere (to have) for verbs that describe motion, state of being, or a change of state. Because diventare (to become) represents a change of state, it takes è as its helper verb.

Why does diventato end in -o?

When you use essere as the helper verb in the past tense, the past participle (the main verb, like diventato) must match the subject in gender and number. Since Mio cugino is masculine singular, diventato ends in -o. If the subject were a female cousin (Mia cugina), it would be è diventata.

Why is it Mio cugino and not Il mio cugino? Don't possessives usually need a 'the' in Italian?

Usually, yes! You generally need a definite article (like il or la) before possessives. However, there is a special exception for family members. For singular, close family members like cugino (cousin), madre (mother), or padre (father), you drop the article and just say Mio cugino.

If I wanted to say 'My cousins became rich,' how would this sentence change?