Do abuser know they are being abusive?

It depends on the abuser. Some of them do it because it's the only way they know and any other "way" doesn't even occur to them (like a dog barking just because another dog barked). They don't understand that they're being abusive.

Others do it intentionally as a way to get what they want.

Then there's a mix of the two, where they'll do it subconsciously. Which is kind of knowing and kind of unknowing.