Learn Italian: Lo studente ha comprato un librone noioso. - The student bought a big boring book.

The word for book is libro. To say a book is very big, you drop the final -o and add the suffix -one, giving you librone. This is an augmentative suffix, which is a handy way to make a noun bigger without needing an extra adjective.

Why does the sentence use lo instead of il for "the student"?

Because studente is a masculine noun that starts with an s followed by another consonant (t). For these words, Italian always uses the article lo instead of il.

Why is noioso placed after librone?

In Italian, descriptive adjectives like noioso (boring) usually come after the noun they describe. It ends in -o because it has to match the masculine, singular noun librone.

Why does it say ha comprato instead of just comprato for "bought"?

To say "bought" in the past tense, Italian uses a two-word tense called the passato prossimo. It needs a helper verb (here, ha from avere, meaning "he has") and the past participle of the main verb (comprato from comprare, meaning "to buy").