Keys enum => Fn, IMEConvert, IMENoConvert etc.

I was looking through the Keys enum and found a few I was unfamiliar with…

IMEConvert / IMENoConvert => What do these do? (I know what an IME is…) Can they be activated through an English (British and/or American) keyboard?

Kana, Kanji => These seem to be specific to a Japanese Keyboard. Can they be activated through an English keyboard?

Fn => I have this on my keyboard, but can’t tell which key enum it would be equivalent to.

Any help is appreciated. Thanks.