I must decide you must decide she must decide we must decide you must decide they must decide
V-ing form
I must be deciding you must be deciding she must be deciding we must be deciding you must be deciding they must be deciding
Perfect
I must have decided you must have decided she must have decided we must have decided you must have decided they must have decided
V-ing perfect
I must have been deciding you must have been deciding she must have been deciding we must have been deciding you must have been deciding they must have been deciding
Negation
Simple form
I must not decide you must not decide she must not decide we must not decide you must not decide they must not decide
V-ing form
I must not be deciding you must not be deciding she must not be deciding we must not be deciding you must not be deciding they must not be deciding
Perfect
I must not have decided you must not have decided she must not have decided we must not have decided you must not have decided they must not have decided
V-ing perfect
I must not have been deciding you must not have been deciding she must not have been deciding we must not have been deciding you must not have been deciding they must not have been deciding
Interrogative form
Simple form
must I decide? must you decide? must she decide? must we decide? must you decide? must they decide?
V-ing form
must I be deciding? must you be deciding? must she be deciding? must we be deciding? must you be deciding? must they be deciding?
Perfect
must I have decided? must you have decided? must she have decided? must we have decided? must you have decided? must they have decided?
V-ing perfect
must I have been deciding? must you have been deciding? must she have been deciding? must we have been deciding? must you have been deciding? must they have been deciding?
Interro-negative form
Simple form
must I not decide? must you not decide? must she not decide? must we not decide? must you not decide? must they not decide?
V-ing form
must I not be deciding? must you not be deciding? must she not be deciding? must we not be deciding? must you not be deciding? must they not be deciding?
Perfect
must I not have decided? must you not have decided? must she not have decided? must we not have decided? must you not have decided? must they not have decided?
V-ing perfect
must I not have been deciding? must you not have been deciding? must she not have been deciding? must we not have been deciding? must you not have been deciding? must they not have been deciding?