could grind
Irregular verb: grind - ground- ground

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could grind
you could grind
she could grind
we could grind
you could grind
they could grind 	I could be grinding
you could be grinding
she could be grinding
we could be grinding
you could be grinding
they could be grinding	I could have ground
you could have ground
she could have ground
we could have ground
you could have ground
they could have ground	I could have been grinding
you could have been grinding
she could have been grinding
we could have been grinding
you could have been grinding
they could have been grinding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't grind
you couldn't grind
she couldn't grind
we couldn't grind
you couldn't grind
they couldn't grind 	I couldn't be grinding
you couldn't be grinding
she couldn't be grinding
we couldn't be grinding
you couldn't be grinding
they couldn't be grinding	I couldn't have ground
you couldn't have ground
she couldn't have ground
we couldn't have ground
you couldn't have ground
they couldn't have ground	I couldn't have been grinding
you couldn't have been grinding
she couldn't have been grinding
we couldn't have been grinding
you couldn't have been grinding
they couldn't have been grinding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I grind?
could you grind?
could she grind?
could we grind?
could you grind?
could they grind? 	could I be grinding?
could you be grinding?
could she be grinding?
could we be grinding?
could you be grinding?
could they be grinding? 	could I have ground?
could you have ground?
could she have ground?
could we have ground?
could you have ground?
could they have ground? 	could I have been grinding?
could you have been grinding?
could she have been grinding?
could we have been grinding?
could you have been grinding?
could they have been grinding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I grind?
couldn't you grind?
couldn't she grind?
couldn't we grind?
couldn't you grind?
couldn't they grind? 	couldn't I be grinding?
couldn't you be grinding?
couldn't she be grinding?
couldn't we be grinding?
couldn't you be grinding?
couldn't they be grinding? 	couldn't I have ground?
couldn't you have ground?
couldn't she have ground?
couldn't we have ground?
couldn't you have ground?
couldn't they have ground? 	couldn't I have been grinding?
couldn't you have been grinding?
couldn't she have been grinding?
couldn't we have been grinding?
couldn't you have been grinding?
couldn't they have been grinding?