I could grubstake you could grubstake he could grubstake we could grubstake you could grubstake they could grubstake
V-ing form
I could be grubstaking you could be grubstaking he could be grubstaking we could be grubstaking you could be grubstaking they could be grubstaking
Perfect
I could have grubstaked you could have grubstaked he could have grubstaked we could have grubstaked you could have grubstaked they could have grubstaked
V-ing perfect
I could have been grubstaking you could have been grubstaking he could have been grubstaking we could have been grubstaking you could have been grubstaking they could have been grubstaking
Negation
Simple form
I could not grubstake you could not grubstake he could not grubstake we could not grubstake you could not grubstake they could not grubstake
V-ing form
I could not be grubstaking you could not be grubstaking he could not be grubstaking we could not be grubstaking you could not be grubstaking they could not be grubstaking
Perfect
I could not have grubstaked you could not have grubstaked he could not have grubstaked we could not have grubstaked you could not have grubstaked they could not have grubstaked
V-ing perfect
I could not have been grubstaking you could not have been grubstaking he could not have been grubstaking we could not have been grubstaking you could not have been grubstaking they could not have been grubstaking
Interrogative form
Simple form
could I grubstake? could you grubstake? could he grubstake? could we grubstake? could you grubstake? could they grubstake?
V-ing form
could I be grubstaking? could you be grubstaking? could he be grubstaking? could we be grubstaking? could you be grubstaking? could they be grubstaking?
Perfect
could I have grubstaked? could you have grubstaked? could he have grubstaked? could we have grubstaked? could you have grubstaked? could they have grubstaked?
V-ing perfect
could I have been grubstaking? could you have been grubstaking? could he have been grubstaking? could we have been grubstaking? could you have been grubstaking? could they have been grubstaking?
Interro-negative form
Simple form
could I not grubstake? could you not grubstake? could he not grubstake? could we not grubstake? could you not grubstake? could they not grubstake?
V-ing form
could I not be grubstaking? could you not be grubstaking? could he not be grubstaking? could we not be grubstaking? could you not be grubstaking? could they not be grubstaking?
Perfect
could I not have grubstaked? could you not have grubstaked? could he not have grubstaked? could we not have grubstaked? could you not have grubstaked? could they not have grubstaked?
V-ing perfect
could I not have been grubstaking? could you not have been grubstaking? could he not have been grubstaking? could we not have been grubstaking? could you not have been grubstaking? could they not have been grubstaking?