could calve
Regular verb: calve - calved- calved

Affirmation 	
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I could calve
you could calve
he could calve
we could calve
you could calve
they could calve 	I could be calving
you could be calving
he could be calving
we could be calving
you could be calving
they could be calving	I could have calved
you could have calved
he could have calved
we could have calved
you could have calved
they could have calved	I could have been calving
you could have been calving
he could have been calving
we could have been calving
you could have been calving
they could have been calving	

Negation 	
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I couldn't calve
you couldn't calve
he couldn't calve
we couldn't calve
you couldn't calve
they couldn't calve 	I couldn't be calving
you couldn't be calving
he couldn't be calving
we couldn't be calving
you couldn't be calving
they couldn't be calving	I couldn't have calved
you couldn't have calved
he couldn't have calved
we couldn't have calved
you couldn't have calved
they couldn't have calved	I couldn't have been calving
you couldn't have been calving
he couldn't have been calving
we couldn't have been calving
you couldn't have been calving
they couldn't have been calving	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I calve?
could you calve?
could he calve?
could we calve?
could you calve?
could they calve? 	could I be calving?
could you be calving?
could he be calving?
could we be calving?
could you be calving?
could they be calving? 	could I have calved?
could you have calved?
could he have calved?
could we have calved?
could you have calved?
could they have calved? 	could I have been calving?
could you have been calving?
could he have been calving?
could we have been calving?
could you have been calving?
could they have been calving? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I calve?
couldn't you calve?
couldn't he calve?
couldn't we calve?
couldn't you calve?
couldn't they calve? 	couldn't I be calving?
couldn't you be calving?
couldn't he be calving?
couldn't we be calving?
couldn't you be calving?
couldn't they be calving? 	couldn't I have calved?
couldn't you have calved?
couldn't he have calved?
couldn't we have calved?
couldn't you have calved?
couldn't they have calved? 	couldn't I have been calving?
couldn't you have been calving?
couldn't he have been calving?
couldn't we have been calving?
couldn't you have been calving?
couldn't they have been calving?