could collate
Regular verb: collate - collated- collated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could collate
you could collate
he could collate
we could collate
you could collate
they could collate 	I could be collating
you could be collating
he could be collating
we could be collating
you could be collating
they could be collating	I could have collated
you could have collated
he could have collated
we could have collated
you could have collated
they could have collated	I could have been collating
you could have been collating
he could have been collating
we could have been collating
you could have been collating
they could have been collating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't collate
you couldn't collate
he couldn't collate
we couldn't collate
you couldn't collate
they couldn't collate 	I couldn't be collating
you couldn't be collating
he couldn't be collating
we couldn't be collating
you couldn't be collating
they couldn't be collating	I couldn't have collated
you couldn't have collated
he couldn't have collated
we couldn't have collated
you couldn't have collated
they couldn't have collated	I couldn't have been collating
you couldn't have been collating
he couldn't have been collating
we couldn't have been collating
you couldn't have been collating
they couldn't have been collating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I collate?
could you collate?
could he collate?
could we collate?
could you collate?
could they collate? 	could I be collating?
could you be collating?
could he be collating?
could we be collating?
could you be collating?
could they be collating? 	could I have collated?
could you have collated?
could he have collated?
could we have collated?
could you have collated?
could they have collated? 	could I have been collating?
could you have been collating?
could he have been collating?
could we have been collating?
could you have been collating?
could they have been collating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I collate?
couldn't you collate?
couldn't he collate?
couldn't we collate?
couldn't you collate?
couldn't they collate? 	couldn't I be collating?
couldn't you be collating?
couldn't he be collating?
couldn't we be collating?
couldn't you be collating?
couldn't they be collating? 	couldn't I have collated?
couldn't you have collated?
couldn't he have collated?
couldn't we have collated?
couldn't you have collated?
couldn't they have collated? 	couldn't I have been collating?
couldn't you have been collating?
couldn't he have been collating?
couldn't we have been collating?
couldn't you have been collating?
couldn't they have been collating?