Rule: Use “like” to show comparisons or something that is “similar to” a given thing.

  • Example: Clementines are like tiny oranges.
  • Example: He ate like a pig. 


Rule: Use “such as” to show examples. When "such as" introduces a modifier that is not essential to the meaning of the sentence, commas are required. 

  • Example: Medications such as aspirin help to relive pain.
  • Example: Take an over-the-counter pain reliever, such as aspirin.


Rule: Do not use commas to separate modifiers or word strings that are essential to the meaning of the sentence.

  • Example: The results are used for purposes such as clarifying and condensing information.
  • Example: Words such as street, avenue, and road are abbreviated only in addresses.