Learn Italian: Le mie sorelle sono tornate dalla gita. - My sisters returned from the trip.

We use sono (from essere, to be) because tornare (to return) is a verb of motion. In Italian, verbs that describe moving from one place to another or a change of state take essere as their helper verb in the past tense instead of avere.

Why does tornate end in an -e instead of an -o?

Because the helper verb is essere, the past participle (tornate) acts like an adjective and must match the subject. Since le mie sorelle (my sisters) is a feminine plural subject, the ending changes to -e.

Why do we need the article Le before mie sorelle? Doesn't Italian drop the article for family members?

You normally drop the article for singular, unmodified family members (like mia sorella). However, when the family member is plural (like sorelle), you must bring the article back! So it becomes le mie sorelle.

What two words make up dalla?

dalla is made by combining the preposition da (from) and the definite article la (the). We use la here because gita (trip) is a feminine singular noun.