I must smell you must smell she must smell we must smell you must smell they must smell
V-ing form
I must be smelling you must be smelling she must be smelling we must be smelling you must be smelling they must be smelling
Perfect
I must have smelled, smelt you must have smelled, smelt she must have smelled, smelt we must have smelled, smelt you must have smelled, smelt they must have smelled, smelt
V-ing perfect
I must have been smelling you must have been smelling she must have been smelling we must have been smelling you must have been smelling they must have been smelling
Negation
Simple form
I must not smell you must not smell she must not smell we must not smell you must not smell they must not smell
V-ing form
I must not be smelling you must not be smelling she must not be smelling we must not be smelling you must not be smelling they must not be smelling
Perfect
I must not have smelled, smelt you must not have smelled, smelt she must not have smelled, smelt we must not have smelled, smelt you must not have smelled, smelt they must not have smelled, smelt
V-ing perfect
I must not have been smelling you must not have been smelling she must not have been smelling we must not have been smelling you must not have been smelling they must not have been smelling
Interrogative form
Simple form
must I smell? must you smell? must she smell? must we smell? must you smell? must they smell?
V-ing form
must I be smelling? must you be smelling? must she be smelling? must we be smelling? must you be smelling? must they be smelling?
Perfect
must I have smelled, smelt? must you have smelled, smelt? must she have smelled, smelt? must we have smelled, smelt? must you have smelled, smelt? must they have smelled, smelt?
V-ing perfect
must I have been smelling? must you have been smelling? must she have been smelling? must we have been smelling? must you have been smelling? must they have been smelling?
Interro-negative form
Simple form
must I not smell? must you not smell? must she not smell? must we not smell? must you not smell? must they not smell?
V-ing form
must I not be smelling? must you not be smelling? must she not be smelling? must we not be smelling? must you not be smelling? must they not be smelling?
Perfect
must I not have smelled, smelt? must you not have smelled, smelt? must she not have smelled, smelt? must we not have smelled, smelt? must you not have smelled, smelt? must they not have smelled, smelt?
V-ing perfect
must I not have been smelling? must you not have been smelling? must she not have been smelling? must we not have been smelling? must you not have been smelling? must they not have been smelling?