Problem with some english words

[Mudbill]

It's wrong. It looks okay but some words are just not the way you think.

For example "accidentally" is not written "accidently" though a lot of people use the latter; even some dictionaries. The original adverb is "accidental" though, so the former is the most correct version.

There are many words that are like this. Some variations are accepted though, but some are definitely not.