Is it side effect or affect?

The correct version is “side effect.” In this instance, “effect” is part of a compound noun and cannot be replaced with another word.

However, in other instances, you can determine whether you should use affect or effect by replacing “effect” with a similar noun (such as “outcome”).

  • If the sentence still makes sense, “effect” is correct.
  • If it doesn’t, you probably mean “affect.”

When in doubt, use QuillBot’s free grammar checker to prevent mistakes!