effect和affect用法有何分別?

effect 是 noun.
It means 結果,效果,影響
For example:
This had a great effect upon the future of both mother and son.
這對母子倆的將來影響很大。

affect 是 verb.
It means 影響.
For example:
The amount of rain affects the growth of crops.
雨量影響作物的生長。

one more uncommon usage
affect CAN be a noun, the meaning being: emotion

this usage is mostly found in the field of psychology, but I just thought I would make it clear that it can be a noun too, not just a verb.

effect=noun
affect=verb

effect =名詞
Affect=動詞

effect ＝名詞
Affect＝動詞

Being lazy affected my grades
去影響（動）

Being lazy has a negative effect on my grades
有影響（名）