Believe it or not, I do have, on occasion, issues with spelling certain words. Conscious and conscience is one such issue.
I finally mastered the difference between the two when a reader of my fanfic mentioned I misused the word, so I looked it up and seared that information into my brain.
Conscious- (adjective) aware, mentally alert.
Conscience- (noun) moral right and wrong.
Being one is an adjective while the other is a noun changes when I use it in a sentence.
Another confusion consists of affect and effect. Effect is a noun, meaning something like special effects. Being affected means something being acted upon.
It just shows you that our language isn’t an easy one to learn, even for those who speak it since infancy.