We use continuous forms for actions and happenings that have started but not finished (they are eating / it is raining etc.). Some verbs (for example, know and like) are not normally used in this way. We don’t say ‘I am knowing’ or ‘they are liking’; we say ‘I know‘, ‘they like‘.
The following verbs are not normally used in the present continuous:
Like, love, hate, want, need, prefer, know, realize, suppose, mean, understand, believe, remember





