'affect' and 'effect' can be both be nouns and verbs. As you might imagine, it can get confusing distinguishing between the two. Worse yet, far too many people (incorrectly) pronounce both words the same way, meaning even experienced English language speakers sometimes mix up these words.
As a verb, 'affect' means "to produce a change in". For example, "The loud noise affected John." This means that loud noise produced a change in John. You are on the right track when you notice that you can either 1) change the tense of the word: "The loud noise will affect John and startle him," or 2) substitute the word with another verb: "The loud noise will frighten John and startle him."
Annoyingly, we can use "affect" as a noun to describe an emotion in a psychological context: "Nervousness is a common affect of neuroticism."
Almost always, we use the word 'effect' as a noun. It means 'result', or 'consequence', therefore a simple way to know if you are using the word properly is to substitute 'result' for 'effect', like this: "What is the effect of drinking too much alcohol?" "What is the result of drinking too much alcohol?" ✔️
As you can see, that works just fine. However… "How does alcohol effect you?" "How does alcohol result you?" ✖️
Unfortunately, we can also use 'effect' as a verb, for example, "Let us effect better education through better curricula." In this sense, 'effect' is the same as 'make', and the two words are interchangeable: "Let us make [for] better education through better curricula." If you can change the tense of the word 'effect' and the sentence is still grammatically correct, then you are using its verb form correctly, like this: "We effected better education through better curricula."
What's the difference between Affect and Effect?
Here's a useful mnemonic to help you remember: R = Remember A = Affect is V = a Verb E = Effect is N = a Noun