These two sets of words present two different problems. The first, affect and effect, is that two words sound alike and are formally distinguished by vowels that can be easily confused for one another. Nevertheless, affect and effect do mean different things. As a noun, affect usually refers a pretense, “He took on a certain affect.” As a verb affect refers to a subjective change in one. “The film powerfully affected him.” Effect refers to a consequence both as a noun and a verb. “The effect of this decision was the produce confusion.” As a verb it means to produce a change. “The Board of Directors effected many changes in policy.” How to distinguish them in your mind? Think of affect relative to feelings and effect relative to consequence. An affect may be an effect but an affect cannot, of itself effect anything.
Sex and gender are two distinct things that are also frequently confused for one another. As a noun, sex refers to a biological category, males and females. Despite whatever told these days, there are still only two sexes, male and female. Gender, however, is a grammatical category and is often arbitrary. E.g., the relative pronoun for a ship is she not because ships are inherently feminine (despite the great lot of nonsense one sees on the web concerning this) but because in Latin the noun for ship is navis, which is a feminine noun. The English word ship is derived from Old English and Germanic words (a version of which is still in use in the word skiff, a flat-bottomed boat) but in usage it was probably assigned it to the female gender following the Latin pattern. Remember, until very recently just about everyone learned Latin and it wasn’t all that long ago that university lectures were still given in Latin. Those patterns had a tremendous influence on English usage, even if, because of the recent collapse of the education system, we’re no longer aware of it. There is a difference between sex, which refers to nature, and gender, which refers to grammar. They are not the same things. That we think they are interchangeable says something about where we are as a culture. It’s another small signal that the culture has convinced itself that reality is an arbitrary construct that can be deconstructed (and reconstructed) at will.
“Let us build a city and tower with its top in the heavens….” (Gen 11:4).