Learn Italian: Questi libri sono difficili, ma lo sport è facile. - These books are difficult, but sport is easy.

In Italian, masculine nouns usually take the article il. However, because sport starts with an s followed by another consonant, you must use lo. Saying il sport is hard to pronounce, so lo sport makes it flow better.

Why does the Italian sentence use lo before sport when the English translation has no article?

In English, we often drop articles when talking about things in general. In Italian, you almost always need to include a definite article like il, la, or lo when talking about broad categories or general concepts.

Why does the adjective difficili end in -i?

The singular form of the word for difficult is difficile. In Italian, adjectives that end in -e in the singular are used for both masculine and feminine nouns. To make them plural, the -e always changes to an -i. Since libri is plural, difficile becomes difficili.

Does the borrowed word sport change if I want to make it plural?

No, it stays exactly the same! When Italian borrows foreign words that end in a consonant, they are usually masculine and do not change their spelling in the plural. To make it plural, you only change the words around it, like using a plural article.