Here is a post about the two grammatical items people most often get wrong, with “affect vs effect” being the first of those items.
TIP: When used as a noun, effect will usually have an article in front of it: the effect, an effect, the uncertainty effect, to have an effect, etc. A clue to the use of effect and affect as verbs is the presence of a helping verb in front of them: will effect [a change], may affect.
And so on. This is a fine post, not so long it falls into the tl;dr category– clear and helpful partly because it’s rather brief.
Now. Back when I was writing papers in grad school, including my master’s thesis, I had to sort out this particular pair of terms. There are zero good synonyms for either word. If you write real science papers, you are going to be using both over and over and over, and at that point you have to figure out how to feel which word is correct in which usage quickly and accurately or you will go nuts.
That was even more true before the control-f command would let you quickly find and look at each instance of each word. It was probably even more true than that before grammar checkers, but since I turn grammar checkers off, I’m not sure how reliable they are with these two words.
So, in case it helps someone else, here’s how I sorted this out.
Quickly change the tense of the sentence from past to present or vice versa. Did “effect” change? Then it should have been “affect,” because the thing that changes when you change verb tense is a verb. This is easier than just saying, “Hey, is that thing there a verb?” You can just stare at a sentence for a shockingly long time wondering if you ever really learned what verbs are or what. Rather than doing that, change the verb tense of the sentence and poof! The verbs jump up waving little flags.
Anyway, that’s what worked for me. That’s what I did in my head, over and over, until I stopped having to ask myself whether to use “affect” or “effect.”
While it’s true that “effect” can be a verb, no one has to worry about that because it doesn’t come up very often and when it does, you’ll notice. Ditto for “affect” as a noun.
I do like noticing that “effect” usually takes an article in front of it. I don’t believe I ever taught myself to look for that, but sure, that’s another good way to quickly and easily check which word you ought to be using.