I must undermine you must undermine she must undermine we must undermine you must undermine they must undermine
V-ing form
I must be undermining you must be undermining she must be undermining we must be undermining you must be undermining they must be undermining
Perfect
I must have undermined you must have undermined she must have undermined we must have undermined you must have undermined they must have undermined
V-ing perfect
I must have been undermining you must have been undermining she must have been undermining we must have been undermining you must have been undermining they must have been undermining
Negation
Simple form
I must not undermine you must not undermine she must not undermine we must not undermine you must not undermine they must not undermine
V-ing form
I must not be undermining you must not be undermining she must not be undermining we must not be undermining you must not be undermining they must not be undermining
Perfect
I must not have undermined you must not have undermined she must not have undermined we must not have undermined you must not have undermined they must not have undermined
V-ing perfect
I must not have been undermining you must not have been undermining she must not have been undermining we must not have been undermining you must not have been undermining they must not have been undermining
Interrogative form
Simple form
must I undermine? must you undermine? must she undermine? must we undermine? must you undermine? must they undermine?
V-ing form
must I be undermining? must you be undermining? must she be undermining? must we be undermining? must you be undermining? must they be undermining?
Perfect
must I have undermined? must you have undermined? must she have undermined? must we have undermined? must you have undermined? must they have undermined?
V-ing perfect
must I have been undermining? must you have been undermining? must she have been undermining? must we have been undermining? must you have been undermining? must they have been undermining?
Interro-negative form
Simple form
must I not undermine? must you not undermine? must she not undermine? must we not undermine? must you not undermine? must they not undermine?
V-ing form
must I not be undermining? must you not be undermining? must she not be undermining? must we not be undermining? must you not be undermining? must they not be undermining?
Perfect
must I not have undermined? must you not have undermined? must she not have undermined? must we not have undermined? must you not have undermined? must they not have undermined?
V-ing perfect
must I not have been undermining? must you not have been undermining? must she not have been undermining? must we not have been undermining? must you not have been undermining? must they not have been undermining?