Learn Italian: Il tennis è uno sport divertente.

In Italian, you generally use definite articles (il, la, etc.) before the names of sports, abstract nouns, and broad categories when talking about them in a general sense. So, "Tennis is a fun sport" needs the Il at the beginning.

Why use uno instead of un for "a sport"?

You must use the indefinite article uno before masculine nouns that start with an 's' followed by another consonant (like the 'sp' in sport). Words starting with 'z', 'ps', 'gn', and 'y' also use uno.

Why is the word order sport divertente instead of divertente sport?

In Italian, descriptive adjectives typically come after the noun they modify. While in English we say "a fun sport," Italian flips this to "a sport fun" (uno sport divertente).

Sport is a masculine noun. Why doesn't divertente end in -o?

Not all adjectives end in -o or -a. Divertente belongs to a group of adjectives that end in -e in their singular form. These adjectives use the exact same -e ending whether the noun is masculine or feminine.