Avere or essere: how to pick the right Italian auxiliary every time

Every Italian compound tense is two pieces: an auxiliary and a past participle. Get the participle wrong and you sound like a learner. Get the auxiliary wrong and you're forced into a second error immediately afterwards, because essere makes the participle agree and avere doesn't.

That compounding is why this is worth getting right early.

The default is avere

Most Italian verbs take avere. If you know nothing about a verb, avere is the better guess, and with avere the participle never changes:

Ho parlato. Abbiamo parlato. Hanno parlato. I spoke. We spoke. They spoke.

One participle, six persons, no agreement. This is the easy half.

Essere covers a coherent group

Essere isn't a random list. It covers three things:

Movement and change of state. Andare, venire, arrivare, partire, uscire, entrare, salire, scendere, tornare, restare, rimanere, nascere, morire, diventare, crescere. The underlying idea: the subject isn't acting on something, the subject is going somewhere or becoming something.

Essere and stare themselves. Both take essere, and both share the participle stato.

Every reflexive verb. No exceptions. Even when the non-reflexive version takes avere:

Ho lavato la macchina. → Mi sono lavato. I washed the car. → I washed (myself).

With essere, the participle agrees

This is the part that catches people. The participle behaves like an adjective and matches the subject in gender and number:

Subject	Form
a man	sono andato
a woman	sono andata
a group of men, or a mixed group	siamo andati
a group of women	siamo andate

Note the mixed-group rule: one man in a group of nine women still gives andati. That's Italian grammar, not a typo.

Every verb page on this site shows the feminine forms alongside the masculine for exactly this reason. Andare is a good one to look at.

The verbs that take both

A small group accepts either auxiliary, and the choice changes the meaning. The pattern is consistent: with a direct object it's avere, without one it's essere.

Verb	With avere	With essere
correre	Ho corso in palestra (I ran, at the gym)	Sono corso a casa (I ran home)
passare	Ho passato l'esame (I passed the exam)	Sono passato da Marco (I stopped by Marco's)
cambiare	Ho cambiato idea (I changed my mind)	Sono cambiato (I've changed)
salire	Ho salito le scale (I climbed the stairs)	Sono salito (I went up)

If there's a thing being acted on, use avere. If the subject is just moving or transforming, use essere.

Modal verbs borrow

Dovere, potere and volere don't have an auxiliary of their own. They take the one belonging to the infinitive that follows:

Sono dovuto andare. (andare takes essere) Ho dovuto studiare. (studiare takes avere)

Spoken Italian increasingly uses avere for both, and you'll hear ho dovuto andare constantly. It isn't what an exam will accept.

The fastest way to internalise it

Don't memorise a list of essere verbs in the abstract. Learn each verb with its auxiliary from the first time you meet it, the way you'd learn a German noun with its article. Andare, essere. Mangiare, avere.

Every conjugation page here labels the auxiliary in the header for that reason. If you want the group in one place, there's a list of verbs that take essere, ordered by how often you'll actually need them.