could mortise
Regular verb: mortise - mortised- mortised

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could mortise
you could mortise
he could mortise
we could mortise
you could mortise
they could mortise 	I could be mortising
you could be mortising
he could be mortising
we could be mortising
you could be mortising
they could be mortising	I could have mortised
you could have mortised
he could have mortised
we could have mortised
you could have mortised
they could have mortised	I could have been mortising
you could have been mortising
he could have been mortising
we could have been mortising
you could have been mortising
they could have been mortising	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not mortise
you could not mortise
he could not mortise
we could not mortise
you could not mortise
they could not mortise 	I could not be mortising
you could not be mortising
he could not be mortising
we could not be mortising
you could not be mortising
they could not be mortising	I could not have mortised
you could not have mortised
he could not have mortised
we could not have mortised
you could not have mortised
they could not have mortised	I could not have been mortising
you could not have been mortising
he could not have been mortising
we could not have been mortising
you could not have been mortising
they could not have been mortising	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I mortise?
could you mortise?
could he mortise?
could we mortise?
could you mortise?
could they mortise? 	could I be mortising?
could you be mortising?
could he be mortising?
could we be mortising?
could you be mortising?
could they be mortising? 	could I have mortised?
could you have mortised?
could he have mortised?
could we have mortised?
could you have mortised?
could they have mortised? 	could I have been mortising?
could you have been mortising?
could he have been mortising?
could we have been mortising?
could you have been mortising?
could they have been mortising? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not mortise?
could you not mortise?
could he not mortise?
could we not mortise?
could you not mortise?
could they not mortise? 	could I not be mortising?
could you not be mortising?
could he not be mortising?
could we not be mortising?
could you not be mortising?
could they not be mortising? 	could I not have mortised?
could you not have mortised?
could he not have mortised?
could we not have mortised?
could you not have mortised?
could they not have mortised? 	could I not have been mortising?
could you not have been mortising?
could he not have been mortising?
could we not have been mortising?
could you not have been mortising?
could they not have been mortising?