1) ALLITERATE/ILLITERATE
Pairs of words with the same initial sound alliterate, like “wild and wooly.” Those who can’t read are illiterate.
2) ALLS / ALL
“Alls I know is . . .” may result from anticipating the “S” in “is,” but the standard expression is “All I know is. . . .”
3) ALLUDE/ELUDE
You can allude (refer) to your daughter’s membership in the honor society when boasting about her, but a criminal tries to elude (escape) captivity. There is no such word as “illude.”
4) ALLUDE/REFER
To allude to something is to refer to it indirectly, by suggestion. If you are being direct and unambiguous, you refer to the subject rather than alluding to it.
5) ALLUSION/ILLUSION
An allusion is a reference, something you allude to: “Her allusion to flowers reminded me that Valentine’s Day was coming.” In that English paper, don’t write “literary illusions” when you mean “allusions.” A mirage, hallucination, or a magic trick is an illusion. (Doesn’t being fooled just make you ill?)