could differ
Regular verb: differ - differed- differed

Affirmation 	
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I could differ
you could differ
he could differ
we could differ
you could differ
they could differ 	I could be differing
you could be differing
he could be differing
we could be differing
you could be differing
they could be differing	I could have differed
you could have differed
he could have differed
we could have differed
you could have differed
they could have differed	I could have been differing
you could have been differing
he could have been differing
we could have been differing
you could have been differing
they could have been differing	

Negation 	
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I couldn't differ
you couldn't differ
he couldn't differ
we couldn't differ
you couldn't differ
they couldn't differ 	I couldn't be differing
you couldn't be differing
he couldn't be differing
we couldn't be differing
you couldn't be differing
they couldn't be differing	I couldn't have differed
you couldn't have differed
he couldn't have differed
we couldn't have differed
you couldn't have differed
they couldn't have differed	I couldn't have been differing
you couldn't have been differing
he couldn't have been differing
we couldn't have been differing
you couldn't have been differing
they couldn't have been differing	

Interrogative form 	
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could I differ?
could you differ?
could he differ?
could we differ?
could you differ?
could they differ? 	could I be differing?
could you be differing?
could he be differing?
could we be differing?
could you be differing?
could they be differing? 	could I have differed?
could you have differed?
could he have differed?
could we have differed?
could you have differed?
could they have differed? 	could I have been differing?
could you have been differing?
could he have been differing?
could we have been differing?
could you have been differing?
could they have been differing? 	

Interro-negative form 	
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couldn't I differ?
couldn't you differ?
couldn't he differ?
couldn't we differ?
couldn't you differ?
couldn't they differ? 	couldn't I be differing?
couldn't you be differing?
couldn't he be differing?
couldn't we be differing?
couldn't you be differing?
couldn't they be differing? 	couldn't I have differed?
couldn't you have differed?
couldn't he have differed?
couldn't we have differed?
couldn't you have differed?
couldn't they have differed? 	couldn't I have been differing?
couldn't you have been differing?
couldn't he have been differing?
couldn't we have been differing?
couldn't you have been differing?
couldn't they have been differing?