could grubstake
Regular verb: grubstake - grubstaked- grubstaked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could grubstake
you could grubstake
she could grubstake
we could grubstake
you could grubstake
they could grubstake 	I could be grubstaking
you could be grubstaking
she could be grubstaking
we could be grubstaking
you could be grubstaking
they could be grubstaking	I could have grubstaked
you could have grubstaked
she could have grubstaked
we could have grubstaked
you could have grubstaked
they could have grubstaked	I could have been grubstaking
you could have been grubstaking
she could have been grubstaking
we could have been grubstaking
you could have been grubstaking
they could have been grubstaking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't grubstake
you couldn't grubstake
she couldn't grubstake
we couldn't grubstake
you couldn't grubstake
they couldn't grubstake 	I couldn't be grubstaking
you couldn't be grubstaking
she couldn't be grubstaking
we couldn't be grubstaking
you couldn't be grubstaking
they couldn't be grubstaking	I couldn't have grubstaked
you couldn't have grubstaked
she couldn't have grubstaked
we couldn't have grubstaked
you couldn't have grubstaked
they couldn't have grubstaked	I couldn't have been grubstaking
you couldn't have been grubstaking
she couldn't have been grubstaking
we couldn't have been grubstaking
you couldn't have been grubstaking
they couldn't have been grubstaking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I grubstake?
could you grubstake?
could she grubstake?
could we grubstake?
could you grubstake?
could they grubstake? 	could I be grubstaking?
could you be grubstaking?
could she be grubstaking?
could we be grubstaking?
could you be grubstaking?
could they be grubstaking? 	could I have grubstaked?
could you have grubstaked?
could she have grubstaked?
could we have grubstaked?
could you have grubstaked?
could they have grubstaked? 	could I have been grubstaking?
could you have been grubstaking?
could she have been grubstaking?
could we have been grubstaking?
could you have been grubstaking?
could they have been grubstaking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I grubstake?
couldn't you grubstake?
couldn't she grubstake?
couldn't we grubstake?
couldn't you grubstake?
couldn't they grubstake? 	couldn't I be grubstaking?
couldn't you be grubstaking?
couldn't she be grubstaking?
couldn't we be grubstaking?
couldn't you be grubstaking?
couldn't they be grubstaking? 	couldn't I have grubstaked?
couldn't you have grubstaked?
couldn't she have grubstaked?
couldn't we have grubstaked?
couldn't you have grubstaked?
couldn't they have grubstaked? 	couldn't I have been grubstaking?
couldn't you have been grubstaking?
couldn't she have been grubstaking?
couldn't we have been grubstaking?
couldn't you have been grubstaking?
couldn't they have been grubstaking?