When it comes to misunderstanding the proper use of words, knowing the difference between affect versus effect is at the top of the list.

Part of the confusion comes from their shared linguistic roots. Both words stem from the Latin verb facere, which means “to do” or “make.”

But affect is derived from afficere, which means “to do something to” or “to have an influence on.” Effect, on the other hand, comes from efficere, which means, “to make” or “carry out.”

Though they are similar, they aren’t interchangeable. And they do get mixed up — a lot. After you see them used incorrectly so many times, you may begin to wonder if you really know which one you should use.

Don’t worry, though. You can be sure you always get affect versus effect right when you follow this simple rule:

Affect is almost always a verb. It shows how one thing influences another.

Example: My broken finger affected my ability to type fast.

Effect is almost always a noun. It shows the impact or result of something.

Example: The construction outside my office had an effect on my concentration.

Here’s a way to remember which one you should use:

  • Affect = Action (verb)
  • Effect = End result (noun)

Like most grammar rules, this one has exceptions, but they’re not common. If you stick to the rules above and use affect as a verb and effect as a noun, you’ll never go wrong.

Happy writing!