English verb conjugation
COULD SKATEBOARD

Regular verb: skateboard - skateboarded - skateboarded

Affirmation

Simple form	V-ing form
I could skateboard you could skateboard he could skateboard we could skateboard you could skateboard they could skateboard	I could be skateboarding you could be skateboarding he could be skateboarding we could be skateboarding you could be skateboarding they could be skateboarding
Perfect	V-ing perfect
I could have skateboarded you could have skateboarded he could have skateboarded we could have skateboarded you could have skateboarded they could have skateboarded	I could have been skateboarding you could have been skateboarding he could have been skateboarding we could have been skateboarding you could have been skateboarding they could have been skateboarding

Negation

Simple form	V-ing form
I could not skateboard you could not skateboard he could not skateboard we could not skateboard you could not skateboard they could not skateboard	I could not be skateboarding you could not be skateboarding he could not be skateboarding we could not be skateboarding you could not be skateboarding they could not be skateboarding
Perfect	V-ing perfect
I could not have skateboarded you could not have skateboarded he could not have skateboarded we could not have skateboarded you could not have skateboarded they could not have skateboarded	I could not have been skateboarding you could not have been skateboarding he could not have been skateboarding we could not have been skateboarding you could not have been skateboarding they could not have been skateboarding

Interrogative form

Simple form	V-ing form
could I skateboard? could you skateboard? could he skateboard? could we skateboard? could you skateboard? could they skateboard?	could I be skateboarding? could you be skateboarding? could he be skateboarding? could we be skateboarding? could you be skateboarding? could they be skateboarding?
Perfect	V-ing perfect
could I have skateboarded? could you have skateboarded? could he have skateboarded? could we have skateboarded? could you have skateboarded? could they have skateboarded?	could I have been skateboarding? could you have been skateboarding? could he have been skateboarding? could we have been skateboarding? could you have been skateboarding? could they have been skateboarding?

Interro-negative form

Simple form	V-ing form
could I not skateboard? could you not skateboard? could he not skateboard? could we not skateboard? could you not skateboard? could they not skateboard?	could I not be skateboarding? could you not be skateboarding? could he not be skateboarding? could we not be skateboarding? could you not be skateboarding? could they not be skateboarding?
Perfect	V-ing perfect
could I not have skateboarded? could you not have skateboarded? could he not have skateboarded? could we not have skateboarded? could you not have skateboarded? could they not have skateboarded?	could I not have been skateboarding? could you not have been skateboarding? could he not have been skateboarding? could we not have been skateboarding? could you not have been skateboarding? could they not have been skateboarding?