Affect means "to influence or produce a change in something", e.g. The weather affected our plans.

Effect means "a result or consequence of something", e.g. The effect of the storm was devastating.

Effect can also be a verb meaning "to cause or bring about something", e.g. The new law will effect some changes in the system.

Affect can also be a noun meaning "an emotion or feeling", e.g. She showed no affect when she heard the news.

You can use the acronym RAVEN: Remember Affect Verb Effect Noun, or think of A for action and E for end result, to help you choose the right word. ^{2 3 4 5}