Learn Romanian: Copilul are capul mare. - The child has a big head.

In Romanian, the word for "the" (the definite article) attaches directly to the end of the noun instead of being a separate word in front. For masculine and neuter nouns ending in a consonant, like copil (child) and cap (head), you add -ul to get copilul (the child) and capul (the head).

The English translation says "a big head", but doesn't capul mean "the head"?

Yes! Literally, this sentence translates to "The child has the head big." When talking about body parts, Romanian typically uses the definite article ("the") where English uses "a" or a possessive word like "his" or "her".

Why does mare (big) come after capul (the head)?

In Romanian, adjectives (describing words) almost always come right after the noun they describe. So, instead of saying "the big head", you say capul mare (literally: the head big).

What verb form is are?

Are means "has". It is the "he/she/it" form of the very common irregular verb a avea (to have). Since copilul (the child) acts as a "he" or "she", we use are.