One of the most common mistakes is the misuse of it’s and its. This mistake in a formal email leads to perceptions of unprofessionalism.

It’s is a contraction for it is or it has

  • It's time to go
  • It's been a wonderful day

Its indicates possessive

  • Every dog has its day
  • The cat bit its tail

A good rule of thumb is: if you can replace it with his or her then there is no apostrophe