Hello Eladio I would distinguish between only 3 forms. Your extra forms relate to different tenses, rather than changes in the structure. There are some tenses you've omitted, too: 'I'm getting used to', for instance.
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AnonymousSo, it doesn't change, no matter if is affirmative - negative or interrogative.Agreement is far from universal on this matter. I didn't use to is also frequently advised by grammarians.