Some irregular verbs that have the same base form as the Past form seem to have the regular "ed" form too. The one that I have problems with right now is "wet". I checked with Cambridge online and it seems that "wet" is regular with no alternative forms listed.

He wetted the cloth and tried to rub the mark away.

But when I checked with McMillan, both "wet" and "wetted" are listed, but the examples only show the irregular form (wet). I feel that "wet" is more common, especially in.

He wet his pants.

But it could be that I'm exposed to more American films. Is it one of those BE/AE differences? But normally Cambridge is pretty good at showing these differences.

And the same goes with "fit" too. Can someone please shed some light here? I'm not sure what to tell my students.

Thank you.