could windmill
Regular verb: windmill - windmilled- windmilled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could windmill
you could windmill
he could windmill
we could windmill
you could windmill
they could windmill 	I could be windmilling
you could be windmilling
he could be windmilling
we could be windmilling
you could be windmilling
they could be windmilling	I could have windmilled
you could have windmilled
he could have windmilled
we could have windmilled
you could have windmilled
they could have windmilled	I could have been windmilling
you could have been windmilling
he could have been windmilling
we could have been windmilling
you could have been windmilling
they could have been windmilling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't windmill
you couldn't windmill
he couldn't windmill
we couldn't windmill
you couldn't windmill
they couldn't windmill 	I couldn't be windmilling
you couldn't be windmilling
he couldn't be windmilling
we couldn't be windmilling
you couldn't be windmilling
they couldn't be windmilling	I couldn't have windmilled
you couldn't have windmilled
he couldn't have windmilled
we couldn't have windmilled
you couldn't have windmilled
they couldn't have windmilled	I couldn't have been windmilling
you couldn't have been windmilling
he couldn't have been windmilling
we couldn't have been windmilling
you couldn't have been windmilling
they couldn't have been windmilling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I windmill?
could you windmill?
could he windmill?
could we windmill?
could you windmill?
could they windmill? 	could I be windmilling?
could you be windmilling?
could he be windmilling?
could we be windmilling?
could you be windmilling?
could they be windmilling? 	could I have windmilled?
could you have windmilled?
could he have windmilled?
could we have windmilled?
could you have windmilled?
could they have windmilled? 	could I have been windmilling?
could you have been windmilling?
could he have been windmilling?
could we have been windmilling?
could you have been windmilling?
could they have been windmilling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I windmill?
couldn't you windmill?
couldn't he windmill?
couldn't we windmill?
couldn't you windmill?
couldn't they windmill? 	couldn't I be windmilling?
couldn't you be windmilling?
couldn't he be windmilling?
couldn't we be windmilling?
couldn't you be windmilling?
couldn't they be windmilling? 	couldn't I have windmilled?
couldn't you have windmilled?
couldn't he have windmilled?
couldn't we have windmilled?
couldn't you have windmilled?
couldn't they have windmilled? 	couldn't I have been windmilling?
couldn't you have been windmilling?
couldn't he have been windmilling?
couldn't we have been windmilling?
couldn't you have been windmilling?
couldn't they have been windmilling?