English verb conjugation
CAN WHISTLE

Regular verb: whistle - whistled - whistled

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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