I too appreciate your explanations. I speak broken Polish. My mother's first language was Polish. I am finding my roots.
"Our aunt writes books" isn't correct?!
It isn't correct. "Książkę" is singular and genitive. "Books" translates as "książki" and this is plural and nominative.
"książkę" is actually Accusative singular. Not Genitive, which would also be "książki" (almost all feminine nouns have Nominative plural = Accusative plural = Genitive singular).
Don't you often use ciotka?
Not nowadays, I think. To my own ear it sounds strangely formal. As if you didn't like this aunt. But it works.
Thank you very much for replying all my questions Jellei. My native language is Spanish and I'm really interested in learning , at least, a basic level of this great language. Sucess!