Learn Italian: Il ponte del nord è molto famoso. - The bridge of the north is very famous.

del is an "articulated preposition," meaning it is a preposition combined with a definite article (a word for "the"). Here, it combines di (of) and il (the). Since "north" is il nord in Italian, we combine di + il to make del nord (of the north).

Why is it famoso and not famosa?

famoso (famous) is an adjective describing Il ponte (The bridge). Since ponte is a masculine singular noun, the adjective must match it by taking the masculine singular -o ending.

Will molto change its ending if the noun is feminine or plural?

Not when it means "very"! In this sentence, molto is an adverb describing how famous the bridge is, and adverbs never change their endings. It only changes endings when it means "much" or "many" and describes a noun directly (like molti ponti for "many bridges").

The word ponte ends in -e, so how can we tell it is masculine?

Italian nouns ending in -e can be either masculine or feminine, so you often just have to memorize their gender. However, the sentence gives us a huge hint: the word for "the" used here is il, which is only ever used for masculine singular nouns.