I must swim you must swim she must swim we must swim you must swim they must swim
V-ing form
I must be swimming you must be swimming she must be swimming we must be swimming you must be swimming they must be swimming
Perfect
I must have swum you must have swum she must have swum we must have swum you must have swum they must have swum
V-ing perfect
I must have been swimming you must have been swimming she must have been swimming we must have been swimming you must have been swimming they must have been swimming
Negation
Simple form
I must not swim you must not swim she must not swim we must not swim you must not swim they must not swim
V-ing form
I must not be swimming you must not be swimming she must not be swimming we must not be swimming you must not be swimming they must not be swimming
Perfect
I must not have swum you must not have swum she must not have swum we must not have swum you must not have swum they must not have swum
V-ing perfect
I must not have been swimming you must not have been swimming she must not have been swimming we must not have been swimming you must not have been swimming they must not have been swimming
Interrogative form
Simple form
must I swim? must you swim? must she swim? must we swim? must you swim? must they swim?
V-ing form
must I be swimming? must you be swimming? must she be swimming? must we be swimming? must you be swimming? must they be swimming?
Perfect
must I have swum? must you have swum? must she have swum? must we have swum? must you have swum? must they have swum?
V-ing perfect
must I have been swimming? must you have been swimming? must she have been swimming? must we have been swimming? must you have been swimming? must they have been swimming?
Interro-negative form
Simple form
must I not swim? must you not swim? must she not swim? must we not swim? must you not swim? must they not swim?
V-ing form
must I not be swimming? must you not be swimming? must she not be swimming? must we not be swimming? must you not be swimming? must they not be swimming?
Perfect
must I not have swum? must you not have swum? must she not have swum? must we not have swum? must you not have swum? must they not have swum?
V-ing perfect
must I not have been swimming? must you not have been swimming? must she not have been swimming? must we not have been swimming? must you not have been swimming? must they not have been swimming?