This helpful chart will keep you from cooking your pasta too long.
In a large saucepan or kettle bring water (3 quarts of water for 4 to 8 ounces pasta) to boiling. If desired, add 1 teaspoon salt and 1 tablespoon olive oil or cooking oil to the water to prevent pasta from sticking together. Add pasta a little at a time so the water does not stop boiling. Reduce heat slightly and boil, uncovered, stirring occasionally, for time specified or until the pasta is al dente. Test often for doneness near the end of the cooking time. Drain in a colander. (To cook purchased dried pasta, check the package directions because brands vary.)