Learn Italian: Questo teorema è molto difficile. - This theorem is very difficult.

Questo teorema è molto difficile.

This theorem is very difficult.

Breakdown of Questo teorema è molto difficile.

Questions & Answers about Questo teorema è molto difficile.

Why is it Questo teorema and not Questa teorema since it ends in -a?

Even though it ends in -a, teorema is a masculine noun. It belongs to a special group of words of Greek origin ending in -ma (like problema or sistema). Because it is masculine, it must take the masculine word for 'this', which is questo.

How would I say 'These theorems are very difficult'?

You would say Questi teoremi sono molto difficili. Masculine nouns ending in -ma change their ending to -i in the plural. The adjectives questo and difficile also have to change to their plural forms (questi and difficili) to match the plural noun.

If the sentence were plural, would molto change to molti?

No, molto would stay exactly the same. In this sentence, molto is acting as an adverb meaning 'very', describing how difficult the theorem is. Adverbs never change their endings. You only change molto to match a noun when it means 'many' or 'a lot of' (for example, molti teoremi).

Why doesn't difficile change to difficilo to match the masculine noun teorema?