could stone
Regular verb: stone - stoned- stoned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could stone
you could stone
she could stone
we could stone
you could stone
they could stone 	I could be stoning
you could be stoning
she could be stoning
we could be stoning
you could be stoning
they could be stoning	I could have stoned
you could have stoned
she could have stoned
we could have stoned
you could have stoned
they could have stoned	I could have been stoning
you could have been stoning
she could have been stoning
we could have been stoning
you could have been stoning
they could have been stoning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't stone
you couldn't stone
she couldn't stone
we couldn't stone
you couldn't stone
they couldn't stone 	I couldn't be stoning
you couldn't be stoning
she couldn't be stoning
we couldn't be stoning
you couldn't be stoning
they couldn't be stoning	I couldn't have stoned
you couldn't have stoned
she couldn't have stoned
we couldn't have stoned
you couldn't have stoned
they couldn't have stoned	I couldn't have been stoning
you couldn't have been stoning
she couldn't have been stoning
we couldn't have been stoning
you couldn't have been stoning
they couldn't have been stoning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I stone?
could you stone?
could she stone?
could we stone?
could you stone?
could they stone? 	could I be stoning?
could you be stoning?
could she be stoning?
could we be stoning?
could you be stoning?
could they be stoning? 	could I have stoned?
could you have stoned?
could she have stoned?
could we have stoned?
could you have stoned?
could they have stoned? 	could I have been stoning?
could you have been stoning?
could she have been stoning?
could we have been stoning?
could you have been stoning?
could they have been stoning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I stone?
couldn't you stone?
couldn't she stone?
couldn't we stone?
couldn't you stone?
couldn't they stone? 	couldn't I be stoning?
couldn't you be stoning?
couldn't she be stoning?
couldn't we be stoning?
couldn't you be stoning?
couldn't they be stoning? 	couldn't I have stoned?
couldn't you have stoned?
couldn't she have stoned?
couldn't we have stoned?
couldn't you have stoned?
couldn't they have stoned? 	couldn't I have been stoning?
couldn't you have been stoning?
couldn't she have been stoning?
couldn't we have been stoning?
couldn't you have been stoning?
couldn't they have been stoning?