I must whirl you must whirl he must whirl we must whirl you must whirl they must whirl
V-ing form
I must be whirling you must be whirling he must be whirling we must be whirling you must be whirling they must be whirling
Perfect
I must have whirled you must have whirled he must have whirled we must have whirled you must have whirled they must have whirled
V-ing perfect
I must have been whirling you must have been whirling he must have been whirling we must have been whirling you must have been whirling they must have been whirling
Negation
Simple form
I must not whirl you must not whirl he must not whirl we must not whirl you must not whirl they must not whirl
V-ing form
I must not be whirling you must not be whirling he must not be whirling we must not be whirling you must not be whirling they must not be whirling
Perfect
I must not have whirled you must not have whirled he must not have whirled we must not have whirled you must not have whirled they must not have whirled
V-ing perfect
I must not have been whirling you must not have been whirling he must not have been whirling we must not have been whirling you must not have been whirling they must not have been whirling
Interrogative form
Simple form
must I whirl? must you whirl? must he whirl? must we whirl? must you whirl? must they whirl?
V-ing form
must I be whirling? must you be whirling? must he be whirling? must we be whirling? must you be whirling? must they be whirling?
Perfect
must I have whirled? must you have whirled? must he have whirled? must we have whirled? must you have whirled? must they have whirled?
V-ing perfect
must I have been whirling? must you have been whirling? must he have been whirling? must we have been whirling? must you have been whirling? must they have been whirling?
Interro-negative form
Simple form
must I not whirl? must you not whirl? must he not whirl? must we not whirl? must you not whirl? must they not whirl?
V-ing form
must I not be whirling? must you not be whirling? must he not be whirling? must we not be whirling? must you not be whirling? must they not be whirling?
Perfect
must I not have whirled? must you not have whirled? must he not have whirled? must we not have whirled? must you not have whirled? must they not have whirled?
V-ing perfect
must I not have been whirling? must you not have been whirling? must he not have been whirling? must we not have been whirling? must you not have been whirling? must they not have been whirling?