could diapause
Regular verb: diapause - diapaused- diapaused

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could diapause
you could diapause
he could diapause
we could diapause
you could diapause
they could diapause 	I could be diapausing
you could be diapausing
he could be diapausing
we could be diapausing
you could be diapausing
they could be diapausing	I could have diapaused
you could have diapaused
he could have diapaused
we could have diapaused
you could have diapaused
they could have diapaused	I could have been diapausing
you could have been diapausing
he could have been diapausing
we could have been diapausing
you could have been diapausing
they could have been diapausing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't diapause
you couldn't diapause
he couldn't diapause
we couldn't diapause
you couldn't diapause
they couldn't diapause 	I couldn't be diapausing
you couldn't be diapausing
he couldn't be diapausing
we couldn't be diapausing
you couldn't be diapausing
they couldn't be diapausing	I couldn't have diapaused
you couldn't have diapaused
he couldn't have diapaused
we couldn't have diapaused
you couldn't have diapaused
they couldn't have diapaused	I couldn't have been diapausing
you couldn't have been diapausing
he couldn't have been diapausing
we couldn't have been diapausing
you couldn't have been diapausing
they couldn't have been diapausing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I diapause?
could you diapause?
could he diapause?
could we diapause?
could you diapause?
could they diapause? 	could I be diapausing?
could you be diapausing?
could he be diapausing?
could we be diapausing?
could you be diapausing?
could they be diapausing? 	could I have diapaused?
could you have diapaused?
could he have diapaused?
could we have diapaused?
could you have diapaused?
could they have diapaused? 	could I have been diapausing?
could you have been diapausing?
could he have been diapausing?
could we have been diapausing?
could you have been diapausing?
could they have been diapausing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I diapause?
couldn't you diapause?
couldn't he diapause?
couldn't we diapause?
couldn't you diapause?
couldn't they diapause? 	couldn't I be diapausing?
couldn't you be diapausing?
couldn't he be diapausing?
couldn't we be diapausing?
couldn't you be diapausing?
couldn't they be diapausing? 	couldn't I have diapaused?
couldn't you have diapaused?
couldn't he have diapaused?
couldn't we have diapaused?
couldn't you have diapaused?
couldn't they have diapaused? 	couldn't I have been diapausing?
couldn't you have been diapausing?
couldn't he have been diapausing?
couldn't we have been diapausing?
couldn't you have been diapausing?
couldn't they have been diapausing?