Learn Russian: Она надевает юбку.

The word юбка (skirt) is the direct object of the sentence, meaning it is the thing being acted upon. For feminine nouns ending in -а, the ending changes to -у in this situation, which is known as the accusative case.

What is the difference between надевать and одевать?

This is a classic tricky pair! You use надевать when putting an item of clothing on (like a skirt). You use одевать when you are dressing a person or an animal (like dressing a child). Since she is putting on an object, we use надевает.

Why does the verb end in -ет?

The dictionary form of the verb is надевать. Because it ends in -ать, it follows the regular first conjugation pattern. To match она (she), we drop the -ть and add the third-person singular ending, -ет.

Is надевает describing a completed action or an ongoing one?

It is an imperfective verb, so it describes an ongoing or repeated action. It means she is in the process of putting the skirt on right now, or she does it regularly. If we wanted to say she will put it on as a completed future action, we would use the perfective form, наденет.