They are all correct, but mean different things. "Doesn't seem" means that a person isn't acting in a way that would indicate something is true. "Seems not to" is stronger and means that the person is acting in a way that that indicates something is not true. ********* He doesn't seem to love her. It doesn't seem that he loves her. same as - By the way he acts, I'm not sure if he loves her. ********** He seems not to love her. It seems that he doesn't love her. same as - By the way he acts, I think he does not love her.

It seems that he doesn't love her.