I must fitter you must fitter she must fitter we must fitter you must fitter they must fitter
V-ing form
I must be fittering you must be fittering she must be fittering we must be fittering you must be fittering they must be fittering
Perfect
I must have fittered you must have fittered she must have fittered we must have fittered you must have fittered they must have fittered
V-ing perfect
I must have been fittering you must have been fittering she must have been fittering we must have been fittering you must have been fittering they must have been fittering
Negation
Simple form
I must not fitter you must not fitter she must not fitter we must not fitter you must not fitter they must not fitter
V-ing form
I must not be fittering you must not be fittering she must not be fittering we must not be fittering you must not be fittering they must not be fittering
Perfect
I must not have fittered you must not have fittered she must not have fittered we must not have fittered you must not have fittered they must not have fittered
V-ing perfect
I must not have been fittering you must not have been fittering she must not have been fittering we must not have been fittering you must not have been fittering they must not have been fittering
Interrogative form
Simple form
must I fitter? must you fitter? must she fitter? must we fitter? must you fitter? must they fitter?
V-ing form
must I be fittering? must you be fittering? must she be fittering? must we be fittering? must you be fittering? must they be fittering?
Perfect
must I have fittered? must you have fittered? must she have fittered? must we have fittered? must you have fittered? must they have fittered?
V-ing perfect
must I have been fittering? must you have been fittering? must she have been fittering? must we have been fittering? must you have been fittering? must they have been fittering?
Interro-negative form
Simple form
must I not fitter? must you not fitter? must she not fitter? must we not fitter? must you not fitter? must they not fitter?
V-ing form
must I not be fittering? must you not be fittering? must she not be fittering? must we not be fittering? must you not be fittering? must they not be fittering?
Perfect
must I not have fittered? must you not have fittered? must she not have fittered? must we not have fittered? must you not have fittered? must they not have fittered?
V-ing perfect
must I not have been fittering? must you not have been fittering? must she not have been fittering? must we not have been fittering? must you not have been fittering? must they not have been fittering?