Breakdown of Marco è inaffidabile, quindi non ho creduto alla sua promessa.
essere
to be
non
not
Marco
Marco
suo
his/her/Your
Questions & Answers about Marco è inaffidabile, quindi non ho creduto alla sua promessa.
How is the adjective inaffidabile formed?
Why is it alla sua promessa instead of just la sua promessa?
The verb credere requires the preposition a when it means believing a person, a statement, or a promise. Here, the preposition a combines with the definite article la (which is needed for the possessive sua) to form the articulated preposition alla.
Could I drop the article and just say a sua promessa?
No, Italian possessive adjectives almost always require a definite article, which is why we must use alla instead of just a. The main exception is for singular family members (like a suo fratello), but since promessa is a regular noun, the article is absolutely mandatory.
If I wanted to expand this sentence to say "his promise that he would arrive", how could I apply the colloquial imperfetto from this lesson?