English verb conjugation
MUST STIFLE

Regular verb: stifle - stifled - stifled

Affirmation

Simple form	V-ing form
I must stifle you must stifle she must stifle we must stifle you must stifle they must stifle	I must be stifling you must be stifling she must be stifling we must be stifling you must be stifling they must be stifling
Perfect	V-ing perfect
I must have stifled you must have stifled she must have stifled we must have stifled you must have stifled they must have stifled	I must have been stifling you must have been stifling she must have been stifling we must have been stifling you must have been stifling they must have been stifling

Negation

Simple form	V-ing form
I must not stifle you must not stifle she must not stifle we must not stifle you must not stifle they must not stifle	I must not be stifling you must not be stifling she must not be stifling we must not be stifling you must not be stifling they must not be stifling
Perfect	V-ing perfect
I must not have stifled you must not have stifled she must not have stifled we must not have stifled you must not have stifled they must not have stifled	I must not have been stifling you must not have been stifling she must not have been stifling we must not have been stifling you must not have been stifling they must not have been stifling

Interrogative form

Simple form	V-ing form
must I stifle? must you stifle? must she stifle? must we stifle? must you stifle? must they stifle?	must I be stifling? must you be stifling? must she be stifling? must we be stifling? must you be stifling? must they be stifling?
Perfect	V-ing perfect
must I have stifled? must you have stifled? must she have stifled? must we have stifled? must you have stifled? must they have stifled?	must I have been stifling? must you have been stifling? must she have been stifling? must we have been stifling? must you have been stifling? must they have been stifling?

Interro-negative form

Simple form	V-ing form
must I not stifle? must you not stifle? must she not stifle? must we not stifle? must you not stifle? must they not stifle?	must I not be stifling? must you not be stifling? must she not be stifling? must we not be stifling? must you not be stifling? must they not be stifling?
Perfect	V-ing perfect
must I not have stifled? must you not have stifled? must she not have stifled? must we not have stifled? must you not have stifled? must they not have stifled?	must I not have been stifling? must you not have been stifling? must she not have been stifling? must we not have been stifling? must you not have been stifling? must they not have been stifling?