Most times a dominant 11th chord is indicated in the music, you can substitute a suspended 7th chord. The formula for a suspended 7th chord is 1 4 5 b7.This is simply a dominant 7th with the 3rd degree raised one semitone (suspended above the 3rd). The symbol for a suspended 7th chord is 7sus or 7sus4. Notice that the Gm7/C chord contains the same notes. Every chord you know can be used in a variety of ways. Experiment!