I have an aversion to adversity.
That’s an easy way to distinguish between “averse” and “adverse.” Averse means “opposed” or “having an antipathy”; adverse means bad, unfavorable, or opposing. Too often people use the latter when they mean the former, as in, “I wouldn’t be adverse to that happening.”
What a difference a “d” makes. Single letters often mark the distinction between proper usage and misuse.
How many times have you heard someone say he was “taking a new tact”? He meant, “taking a new tack.” The word “tact” derives from the word for touch and most often is used to describe delicacy in handling a situation.
“Tack” is a sailing term—to “tack” is a way of varying one’s course. More generally, we use it to mean trying a new approach, as in, “Why don’t you take a new tack and try some tact, you boorish oaf?”