For a small hole: A minor hole in a sweater can be fixed, but you should deal with it immediately, says Jane Rising, manager of training at the International Fabricare Institute, in Laurel, Maryland. A tailor or a dry cleaner can take care of a tiny opening, especially if it's along a seam. (Bring the extra thread that came with the sweater, if you have it.)
For a large hole: If it's the size of a pencil eraser or bigger, it must be rewoven by a tailor, which can get pricey ($35 to $100 a hole).
For a pull: A little string end poking out in a sweater is usually a snap to mend. Just thread the offending yarn through the eye of a needle, then push it through to the inside of the sweater.
Odds of revival: Very high.