I could forest you could forest he could forest we could forest you could forest they could forest
V-ing form
I could be foresting you could be foresting he could be foresting we could be foresting you could be foresting they could be foresting
Perfect
I could have forested you could have forested he could have forested we could have forested you could have forested they could have forested
V-ing perfect
I could have been foresting you could have been foresting he could have been foresting we could have been foresting you could have been foresting they could have been foresting
Negation
Simple form
I could not forest you could not forest he could not forest we could not forest you could not forest they could not forest
V-ing form
I could not be foresting you could not be foresting he could not be foresting we could not be foresting you could not be foresting they could not be foresting
Perfect
I could not have forested you could not have forested he could not have forested we could not have forested you could not have forested they could not have forested
V-ing perfect
I could not have been foresting you could not have been foresting he could not have been foresting we could not have been foresting you could not have been foresting they could not have been foresting
Interrogative form
Simple form
could I forest? could you forest? could he forest? could we forest? could you forest? could they forest?
V-ing form
could I be foresting? could you be foresting? could he be foresting? could we be foresting? could you be foresting? could they be foresting?
Perfect
could I have forested? could you have forested? could he have forested? could we have forested? could you have forested? could they have forested?
V-ing perfect
could I have been foresting? could you have been foresting? could he have been foresting? could we have been foresting? could you have been foresting? could they have been foresting?
Interro-negative form
Simple form
could I not forest? could you not forest? could he not forest? could we not forest? could you not forest? could they not forest?
V-ing form
could I not be foresting? could you not be foresting? could he not be foresting? could we not be foresting? could you not be foresting? could they not be foresting?
Perfect
could I not have forested? could you not have forested? could he not have forested? could we not have forested? could you not have forested? could they not have forested?
V-ing perfect
could I not have been foresting? could you not have been foresting? could he not have been foresting? could we not have been foresting? could you not have been foresting? could they not have been foresting?