commas with such as

To decide whether to use commas with such as, you need to know whether the phrase it introduces is essential.

Commas

When such as introduces a modifier that is not essential to the meaning of the sentence (i.e. a non-restrictive modifier), commas are required:

• Precious gems, such as rubies, are impressive to behold.

The modifier such as rubies is not essential; it simply adds detail. Therefore, it should be set off by commas.

No commas

However, modifiers that are essential to the meaning of the sentence (i.e. restrictive modifiers) are not set off by commas:

• Words such as street, avenue, and road are abbreviated only in addresses.

The modifier such as street, avenue, and road is essential to the meaning of the sentence: it restricts the general term words to a specific type of word. As a result, it should not be set off by commas.

No comma after such as

Note that such as should not be separated from the list of examples that follows it. For that reason, you should never put a comma immediately after such as.

• Incorrect: For PowerPoint presentations, use a font such as, Arial, Trebuchet or Verdana.
• Correct: For PowerPoint presentations, use a font such as Arial, Trebuchet or Verdana.