Learn Romanian: Băiatul are două picioare.

In Romanian, the word for the (the definite article) attaches to the end of the noun instead of being a separate word in front. The base word for boy is băiat. Because it is a masculine noun ending in a consonant, we add -ul to the end to make it băiatul (the boy).

I learned that the number two is doi. Why is it două in this sentence?

Numbers like 1 and 2 change depending on the gender of the noun they describe. Doi is used for masculine nouns, and două is used for feminine nouns. The word for leg, picior, belongs to a third category called neuter nouns, which use două in the plural.

How do neuter nouns like picior work when counting?

Neuter nouns are a mix: they act like masculine nouns when singular, and like feminine nouns when plural. That is why you say un picior (one leg, using the masculine word for one) but două picioare (two legs, using the feminine word for two).

Does picioare mean legs or feet?

It means both! In Romanian, the word picior refers to the entire lower limb, from the hip down to the toes. You use the exact same word whether you are talking about a leg or a foot, and context usually makes your meaning clear.