I must falter you must falter he must falter we must falter you must falter they must falter
V-ing form
I must be faltering you must be faltering he must be faltering we must be faltering you must be faltering they must be faltering
Perfect
I must have faltered you must have faltered he must have faltered we must have faltered you must have faltered they must have faltered
V-ing perfect
I must have been faltering you must have been faltering he must have been faltering we must have been faltering you must have been faltering they must have been faltering
Negation
Simple form
I must not falter you must not falter he must not falter we must not falter you must not falter they must not falter
V-ing form
I must not be faltering you must not be faltering he must not be faltering we must not be faltering you must not be faltering they must not be faltering
Perfect
I must not have faltered you must not have faltered he must not have faltered we must not have faltered you must not have faltered they must not have faltered
V-ing perfect
I must not have been faltering you must not have been faltering he must not have been faltering we must not have been faltering you must not have been faltering they must not have been faltering
Interrogative form
Simple form
must I falter? must you falter? must he falter? must we falter? must you falter? must they falter?
V-ing form
must I be faltering? must you be faltering? must he be faltering? must we be faltering? must you be faltering? must they be faltering?
Perfect
must I have faltered? must you have faltered? must he have faltered? must we have faltered? must you have faltered? must they have faltered?
V-ing perfect
must I have been faltering? must you have been faltering? must he have been faltering? must we have been faltering? must you have been faltering? must they have been faltering?
Interro-negative form
Simple form
must I not falter? must you not falter? must he not falter? must we not falter? must you not falter? must they not falter?
V-ing form
must I not be faltering? must you not be faltering? must he not be faltering? must we not be faltering? must you not be faltering? must they not be faltering?
Perfect
must I not have faltered? must you not have faltered? must he not have faltered? must we not have faltered? must you not have faltered? must they not have faltered?
V-ing perfect
must I not have been faltering? must you not have been faltering? must he not have been faltering? must we not have been faltering? must you not have been faltering? must they not have been faltering?