English verb conjugation
COULD PREBOARD

Regular verb: preboard - preboarded - preboarded

Affirmation

Simple form	V-ing form
I could preboard you could preboard he could preboard we could preboard you could preboard they could preboard	I could be preboarding you could be preboarding he could be preboarding we could be preboarding you could be preboarding they could be preboarding
Perfect	V-ing perfect
I could have preboarded you could have preboarded he could have preboarded we could have preboarded you could have preboarded they could have preboarded	I could have been preboarding you could have been preboarding he could have been preboarding we could have been preboarding you could have been preboarding they could have been preboarding

Negation

Simple form	V-ing form
I could not preboard you could not preboard he could not preboard we could not preboard you could not preboard they could not preboard	I could not be preboarding you could not be preboarding he could not be preboarding we could not be preboarding you could not be preboarding they could not be preboarding
Perfect	V-ing perfect
I could not have preboarded you could not have preboarded he could not have preboarded we could not have preboarded you could not have preboarded they could not have preboarded	I could not have been preboarding you could not have been preboarding he could not have been preboarding we could not have been preboarding you could not have been preboarding they could not have been preboarding

Interrogative form

Simple form	V-ing form
could I preboard? could you preboard? could he preboard? could we preboard? could you preboard? could they preboard?	could I be preboarding? could you be preboarding? could he be preboarding? could we be preboarding? could you be preboarding? could they be preboarding?
Perfect	V-ing perfect
could I have preboarded? could you have preboarded? could he have preboarded? could we have preboarded? could you have preboarded? could they have preboarded?	could I have been preboarding? could you have been preboarding? could he have been preboarding? could we have been preboarding? could you have been preboarding? could they have been preboarding?

Interro-negative form

Simple form	V-ing form
could I not preboard? could you not preboard? could he not preboard? could we not preboard? could you not preboard? could they not preboard?	could I not be preboarding? could you not be preboarding? could he not be preboarding? could we not be preboarding? could you not be preboarding? could they not be preboarding?
Perfect	V-ing perfect
could I not have preboarded? could you not have preboarded? could he not have preboarded? could we not have preboarded? could you not have preboarded? could they not have preboarded?	could I not have been preboarding? could you not have been preboarding? could he not have been preboarding? could we not have been preboarding? could you not have been preboarding? could they not have been preboarding?