English verb conjugation
MUST WHISTLE

Regular verb: whistle - whistled - whistled

Affirmation

Simple form	V-ing form
I must whistle you must whistle he must whistle we must whistle you must whistle they must whistle	I must be whistling you must be whistling he must be whistling we must be whistling you must be whistling they must be whistling
Perfect	V-ing perfect
I must have whistled you must have whistled he must have whistled we must have whistled you must have whistled they must have whistled	I must have been whistling you must have been whistling he must have been whistling we must have been whistling you must have been whistling they must have been whistling

Negation

Simple form	V-ing form
I mustn't whistle you mustn't whistle he mustn't whistle we mustn't whistle you mustn't whistle they mustn't whistle	I mustn't be whistling you mustn't be whistling he mustn't be whistling we mustn't be whistling you mustn't be whistling they mustn't be whistling
Perfect	V-ing perfect
I mustn't have whistled you mustn't have whistled he mustn't have whistled we mustn't have whistled you mustn't have whistled they mustn't have whistled	I mustn't have been whistling you mustn't have been whistling he mustn't have been whistling we mustn't have been whistling you mustn't have been whistling they mustn't have been whistling

Interrogative form

Simple form	V-ing form
must I whistle? must you whistle? must he whistle? must we whistle? must you whistle? must they whistle?	must I be whistling? must you be whistling? must he be whistling? must we be whistling? must you be whistling? must they be whistling?
Perfect	V-ing perfect
must I have whistled? must you have whistled? must he have whistled? must we have whistled? must you have whistled? must they have whistled?	must I have been whistling? must you have been whistling? must he have been whistling? must we have been whistling? must you have been whistling? must they have been whistling?

Interro-negative form

Simple form	V-ing form
mustn't I whistle? mustn't you whistle? mustn't he whistle? mustn't we whistle? mustn't you whistle? mustn't they whistle?	mustn't I be whistling? mustn't you be whistling? mustn't he be whistling? mustn't we be whistling? mustn't you be whistling? mustn't they be whistling?
Perfect	V-ing perfect
mustn't I have whistled? mustn't you have whistled? mustn't he have whistled? mustn't we have whistled? mustn't you have whistled? mustn't they have whistled?	mustn't I have been whistling? mustn't you have been whistling? mustn't he have been whistling? mustn't we have been whistling? mustn't you have been whistling? mustn't they have been whistling?