I think what SOK is saying is change your Aperture to something that INCREASES the DOF of your shot. e.g., If you're shooting at 1.8 - and depending on your Focal length & distance from your subject, it's possible that things won't be in focus as wide as you want them. But that's all about DOF, not "blurry" which is what you initially posted. If you're truly talking about "blurry" pictures, there are many things that could be contributing to that problem : camera shake, too slow SS, etc.
You might want to post a pic for everyone to see the issue - and the exif data that goes with it.