According to Merriam-Webster’s website, these are the 10 most frequently searched terms on the site—not what is trending now, but the words that consistently rank among the top searches.
Another mnemonic to help you distinguish the two is that to affect is to have an effect, and an affect leads to an effect. Affect usually means “have an effect or influence,” as in “Will not completing this assignment affect my grade?” while an effect is something that is the result of a causative phenomenon (hence the phrase “cause and effect”), as in “Will not completing this have an effect on my grade?”
But note that affect can also serve as a noun meaning “aspect of an emotion” or “evidence of an emotion.” In psychology, to say that one presents a flat affect is to express that the person exhibits little or no emotion. In addition, effect is sometimes used as a verb meaning “bring about,” as in “Our goal is to effect a change in policy.” One can also say, “Our goal is to affect a change in policy,” but that means that one merely wishes to have an impact; to effect a change is to deliberately create the change.