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