I can snowboard you can snowboard he can snowboard we can snowboard you can snowboard they can snowboard
V-ing form
I can be snowboarding you can be snowboarding he can be snowboarding we can be snowboarding you can be snowboarding they can be snowboarding
Perfect
I can have snowboarded you can have snowboarded he can have snowboarded we can have snowboarded you can have snowboarded they can have snowboarded
V-ing perfect
I can have been snowboarding you can have been snowboarding he can have been snowboarding we can have been snowboarding you can have been snowboarding they can have been snowboarding
Negation
Simple form
I cannot snowboard you cannot snowboard he cannot snowboard we cannot snowboard you cannot snowboard they cannot snowboard
V-ing form
I cannot be snowboarding you cannot be snowboarding he cannot be snowboarding we cannot be snowboarding you cannot be snowboarding they cannot be snowboarding
Perfect
I cannot have snowboarded you cannot have snowboarded he cannot have snowboarded we cannot have snowboarded you cannot have snowboarded they cannot have snowboarded
V-ing perfect
I cannot have been snowboarding you cannot have been snowboarding he cannot have been snowboarding we cannot have been snowboarding you cannot have been snowboarding they cannot have been snowboarding
Interrogative form
Simple form
can I snowboard? can you snowboard? can he snowboard? can we snowboard? can you snowboard? can they snowboard?
V-ing form
can I be snowboarding? can you be snowboarding? can he be snowboarding? can we be snowboarding? can you be snowboarding? can they be snowboarding?
Perfect
can I have snowboarded? can you have snowboarded? can he have snowboarded? can we have snowboarded? can you have snowboarded? can they have snowboarded?
V-ing perfect
can I have been snowboarding? can you have been snowboarding? can he have been snowboarding? can we have been snowboarding? can you have been snowboarding? can they have been snowboarding?
Interro-negative form
Simple form
can I not snowboard? can you not snowboard? can he not snowboard? can we not snowboard? can you not snowboard? can they not snowboard?
V-ing form
can I not be snowboarding? can you not be snowboarding? can he not be snowboarding? can we not be snowboarding? can you not be snowboarding? can they not be snowboarding?
Perfect
can I not have snowboarded? can you not have snowboarded? can he not have snowboarded? can we not have snowboarded? can you not have snowboarded? can they not have snowboarded?
V-ing perfect
can I not have been snowboarding? can you not have been snowboarding? can he not have been snowboarding? can we not have been snowboarding? can you not have been snowboarding? can they not have been snowboarding?