English verb conjugation
CAN TURN

Regular verb: turn - turned - turned

Affirmation

Simple form	V-ing form
I can turn you can turn he can turn we can turn you can turn they can turn	I can be turning you can be turning he can be turning we can be turning you can be turning they can be turning
Perfect	V-ing perfect
I can have turned you can have turned he can have turned we can have turned you can have turned they can have turned	I can have been turning you can have been turning he can have been turning we can have been turning you can have been turning they can have been turning

Negation

Simple form	V-ing form
I can't turn you can't turn he can't turn we can't turn you can't turn they can't turn	I can't be turning you can't be turning he can't be turning we can't be turning you can't be turning they can't be turning
Perfect	V-ing perfect
I can't have turned you can't have turned he can't have turned we can't have turned you can't have turned they can't have turned	I can't have been turning you can't have been turning he can't have been turning we can't have been turning you can't have been turning they can't have been turning

Interrogative form

Simple form	V-ing form
can I turn? can you turn? can he turn? can we turn? can you turn? can they turn?	can I be turning? can you be turning? can he be turning? can we be turning? can you be turning? can they be turning?
Perfect	V-ing perfect
can I have turned? can you have turned? can he have turned? can we have turned? can you have turned? can they have turned?	can I have been turning? can you have been turning? can he have been turning? can we have been turning? can you have been turning? can they have been turning?

Interro-negative form

Simple form	V-ing form
can't I turn? can't you turn? can't he turn? can't we turn? can't you turn? can't they turn?	can't I be turning? can't you be turning? can't he be turning? can't we be turning? can't you be turning? can't they be turning?
Perfect	V-ing perfect
can't I have turned? can't you have turned? can't he have turned? can't we have turned? can't you have turned? can't they have turned?	can't I have been turning? can't you have been turning? can't he have been turning? can't we have been turning? can't you have been turning? can't they have been turning?