could spot-check
Regular verb: spot-check - spot-checked- spot-checked

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

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

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

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