I could companion you could companion he could companion we could companion you could companion they could companion
V-ing form
I could be companioning you could be companioning he could be companioning we could be companioning you could be companioning they could be companioning
Perfect
I could have companioned you could have companioned he could have companioned we could have companioned you could have companioned they could have companioned
V-ing perfect
I could have been companioning you could have been companioning he could have been companioning we could have been companioning you could have been companioning they could have been companioning
Negation
Simple form
I could not companion you could not companion he could not companion we could not companion you could not companion they could not companion
V-ing form
I could not be companioning you could not be companioning he could not be companioning we could not be companioning you could not be companioning they could not be companioning
Perfect
I could not have companioned you could not have companioned he could not have companioned we could not have companioned you could not have companioned they could not have companioned
V-ing perfect
I could not have been companioning you could not have been companioning he could not have been companioning we could not have been companioning you could not have been companioning they could not have been companioning
Interrogative form
Simple form
could I companion? could you companion? could he companion? could we companion? could you companion? could they companion?
V-ing form
could I be companioning? could you be companioning? could he be companioning? could we be companioning? could you be companioning? could they be companioning?
Perfect
could I have companioned? could you have companioned? could he have companioned? could we have companioned? could you have companioned? could they have companioned?
V-ing perfect
could I have been companioning? could you have been companioning? could he have been companioning? could we have been companioning? could you have been companioning? could they have been companioning?
Interro-negative form
Simple form
could I not companion? could you not companion? could he not companion? could we not companion? could you not companion? could they not companion?
V-ing form
could I not be companioning? could you not be companioning? could he not be companioning? could we not be companioning? could you not be companioning? could they not be companioning?
Perfect
could I not have companioned? could you not have companioned? could he not have companioned? could we not have companioned? could you not have companioned? could they not have companioned?
V-ing perfect
could I not have been companioning? could you not have been companioning? could he not have been companioning? could we not have been companioning? could you not have been companioning? could they not have been companioning?