Studying affects test results; the effect is usually better grades.
Affect [THINK: Action word (A)]
Effect [THINK: End-result (E)]
“The verb affect means “to act on; produce an effect or change in.” …It can also mean “to impress the mind or move the feelings of…”
“Effect is most commonly used as a noun meaning “result” or “consequence…” …It can be used as a verb to mean “make happen,” but that use is less common.”
[read more about it on blog.dictionary.com]