I might be the only one that has trouble remembering which of these is which, but I've finally come up with a method to differentiate between the two without having to open up my dictionary every time. Breath- the air inhaled and exhaled in respiration. Breathe- the act of breathing. For breathe, you sound out the first 'e' when you say it. BrEEEEthe. When you use BrEEEEEthe, put the E at the end.