changeable: The verb “change� keeps its [e] here to indicate that the [g] is soft, not hard. (That is also why “judgement� is the correct spelling of this word, no matter what anyone says.)

committed: If you are committed to correct spelling, you will remember that this word doubles its final [t] from “commit� to “committed.�

experience: Don’t experience the same problem many have with “existence� above in this word: -ence!

lightning: Learning how to omit the [e] in this word should lighten the load of English orthography a little bit

occurrence: Remember not only the occurrence of double double consonants in this word, but that the suffix is -ence, not -ance. No reason, just the English language keeping us on our toes.

Source: YourDictionary.com
Via: lifehack.org