I'm sure I'm missing something obvious here, but why is this only "I have arrived" and not also possibly "They have arrived"?
Edit: I think I just answered my own question later on in the lesson, but I'm throwing it out here in case someone else is wondering the same thing or in case I'm wrong and someone feels like correcting me. Arrivata has to agree with the subject so this would be the appropriate sentence only for a self-referencing female speaker correct? If it was "they" it would be something to the effect of "Sono arrivati alla stazione"?
That's how you conjugate a verb that is using "essere"
- Masculine singular : Sono arrivato
- Feminine singular : Sono arrivata
- Masculine plural : Essi arrivati
- Feminine plural : Essi arrivate
The sentence "Sono arrivata alla stazione." shows that the subject is feminine and singular.
It depends on the verb. Most verbs would use a form of "avere" as the auxiliary verb, as in "ho trovato".
Some verbs use a form of "essere", as in "sono arrivato". Some describe them as verbs of motion. But that can be misleading. I think of them as verbs of coming and going, but that doesn't account for "to stay", for example.
I find it easier to learn them in pairs or groups, like "to be born"/"to die", "to come in"/"to go out", etc. Notice that these verbs don't have a direct object.
Common verbs that use "essere" are :
to come, venire (venuto)
to go, andare (andato)
to enter, entrare
to go out, uscire
to be born, nascere
to die, morire
to arrive, arrivare
to remain, rimanere
to stay, be stare
to leave, partire
to disappear, sparire
to come back/return, tornare
to be, essere
All reflexive verbs use essere as the auxiliary verb.
There are many explanations of the passato prossimo on-line. Here is just one example with an explanation in english : http://www.unc.edu/~achamble/passatoprossimo.html