как будет слово not be able to в правильной глагольной форме?

настоящееI am not able toYou (we, they) aren't able toHe (she, it) isn't able toпрошедшееI (he, she, it) wasn't able toYou (we, they) weren't able toбудущееI (we) shan't be able toHe (she, it, they, you) won't be able to