Answered by Deanna, Hiring Expert at IBM Corporation, on Thursday, March 21, 2013
Incorrect spelling and grammar stand out. Even with spell-check, it is surprising how often mis-spelled words still slip through. I encourage you to very carefully read through your resume - twice. Then ask someone else to as well!
Another red flag is gaps in experience or school that are not explained. It is better to comment on gaps, even recognizing time off, than to leave the time unexplained.
Lastly, not including gpa raises a flag. If gpa is not included, then the common presumption is that it is low. And maybe that is why a candidate would leave it off the resume. But my opinion is to go ahead and communicate the facts, letting the hiring party evaluate you as a candidate with all of the information.