I must stall you must stall she must stall we must stall you must stall they must stall
V-ing form
I must be stalling you must be stalling she must be stalling we must be stalling you must be stalling they must be stalling
Perfect
I must have stalled you must have stalled she must have stalled we must have stalled you must have stalled they must have stalled
V-ing perfect
I must have been stalling you must have been stalling she must have been stalling we must have been stalling you must have been stalling they must have been stalling
Negation
Simple form
I must not stall you must not stall she must not stall we must not stall you must not stall they must not stall
V-ing form
I must not be stalling you must not be stalling she must not be stalling we must not be stalling you must not be stalling they must not be stalling
Perfect
I must not have stalled you must not have stalled she must not have stalled we must not have stalled you must not have stalled they must not have stalled
V-ing perfect
I must not have been stalling you must not have been stalling she must not have been stalling we must not have been stalling you must not have been stalling they must not have been stalling
Interrogative form
Simple form
must I stall? must you stall? must she stall? must we stall? must you stall? must they stall?
V-ing form
must I be stalling? must you be stalling? must she be stalling? must we be stalling? must you be stalling? must they be stalling?
Perfect
must I have stalled? must you have stalled? must she have stalled? must we have stalled? must you have stalled? must they have stalled?
V-ing perfect
must I have been stalling? must you have been stalling? must she have been stalling? must we have been stalling? must you have been stalling? must they have been stalling?
Interro-negative form
Simple form
must I not stall? must you not stall? must she not stall? must we not stall? must you not stall? must they not stall?
V-ing form
must I not be stalling? must you not be stalling? must she not be stalling? must we not be stalling? must you not be stalling? must they not be stalling?
Perfect
must I not have stalled? must you not have stalled? must she not have stalled? must we not have stalled? must you not have stalled? must they not have stalled?
V-ing perfect
must I not have been stalling? must you not have been stalling? must she not have been stalling? must we not have been stalling? must you not have been stalling? must they not have been stalling?