could upend
Regular verb: upend - upended- upended

Affirmation 	
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I could upend
you could upend
he could upend
we could upend
you could upend
they could upend 	I could be upending
you could be upending
he could be upending
we could be upending
you could be upending
they could be upending	I could have upended
you could have upended
he could have upended
we could have upended
you could have upended
they could have upended	I could have been upending
you could have been upending
he could have been upending
we could have been upending
you could have been upending
they could have been upending	

Negation 	
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I could not upend
you could not upend
he could not upend
we could not upend
you could not upend
they could not upend 	I could not be upending
you could not be upending
he could not be upending
we could not be upending
you could not be upending
they could not be upending	I could not have upended
you could not have upended
he could not have upended
we could not have upended
you could not have upended
they could not have upended	I could not have been upending
you could not have been upending
he could not have been upending
we could not have been upending
you could not have been upending
they could not have been upending	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I upend?
could you upend?
could he upend?
could we upend?
could you upend?
could they upend? 	could I be upending?
could you be upending?
could he be upending?
could we be upending?
could you be upending?
could they be upending? 	could I have upended?
could you have upended?
could he have upended?
could we have upended?
could you have upended?
could they have upended? 	could I have been upending?
could you have been upending?
could he have been upending?
could we have been upending?
could you have been upending?
could they have been upending? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not upend?
could you not upend?
could he not upend?
could we not upend?
could you not upend?
could they not upend? 	could I not be upending?
could you not be upending?
could he not be upending?
could we not be upending?
could you not be upending?
could they not be upending? 	could I not have upended?
could you not have upended?
could he not have upended?
could we not have upended?
could you not have upended?
could they not have upended? 	could I not have been upending?
could you not have been upending?
could he not have been upending?
could we not have been upending?
could you not have been upending?
could they not have been upending?