could double-check
Regular verb: double-check - double-checked- double-checked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could double-check
you could double-check
he could double-check
we could double-check
you could double-check
they could double-check 	I could be double-checking
you could be double-checking
he could be double-checking
we could be double-checking
you could be double-checking
they could be double-checking	I could have double-checked
you could have double-checked
he could have double-checked
we could have double-checked
you could have double-checked
they could have double-checked	I could have been double-checking
you could have been double-checking
he could have been double-checking
we could have been double-checking
you could have been double-checking
they could have been double-checking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't double-check
you couldn't double-check
he couldn't double-check
we couldn't double-check
you couldn't double-check
they couldn't double-check 	I couldn't be double-checking
you couldn't be double-checking
he couldn't be double-checking
we couldn't be double-checking
you couldn't be double-checking
they couldn't be double-checking	I couldn't have double-checked
you couldn't have double-checked
he couldn't have double-checked
we couldn't have double-checked
you couldn't have double-checked
they couldn't have double-checked	I couldn't have been double-checking
you couldn't have been double-checking
he couldn't have been double-checking
we couldn't have been double-checking
you couldn't have been double-checking
they couldn't have been double-checking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I double-check?
could you double-check?
could he double-check?
could we double-check?
could you double-check?
could they double-check? 	could I be double-checking?
could you be double-checking?
could he be double-checking?
could we be double-checking?
could you be double-checking?
could they be double-checking? 	could I have double-checked?
could you have double-checked?
could he have double-checked?
could we have double-checked?
could you have double-checked?
could they have double-checked? 	could I have been double-checking?
could you have been double-checking?
could he have been double-checking?
could we have been double-checking?
could you have been double-checking?
could they have been double-checking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I double-check?
couldn't you double-check?
couldn't he double-check?
couldn't we double-check?
couldn't you double-check?
couldn't they double-check? 	couldn't I be double-checking?
couldn't you be double-checking?
couldn't he be double-checking?
couldn't we be double-checking?
couldn't you be double-checking?
couldn't they be double-checking? 	couldn't I have double-checked?
couldn't you have double-checked?
couldn't he have double-checked?
couldn't we have double-checked?
couldn't you have double-checked?
couldn't they have double-checked? 	couldn't I have been double-checking?
couldn't you have been double-checking?
couldn't he have been double-checking?
couldn't we have been double-checking?
couldn't you have been double-checking?
couldn't they have been double-checking?