could preexchange
Regular verb: preexchange - preexchanged- preexchanged

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could preexchange
you could preexchange
he could preexchange
we could preexchange
you could preexchange
they could preexchange 	I could be preexchanging
you could be preexchanging
he could be preexchanging
we could be preexchanging
you could be preexchanging
they could be preexchanging	I could have preexchanged
you could have preexchanged
he could have preexchanged
we could have preexchanged
you could have preexchanged
they could have preexchanged	I could have been preexchanging
you could have been preexchanging
he could have been preexchanging
we could have been preexchanging
you could have been preexchanging
they could have been preexchanging	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't preexchange
you couldn't preexchange
he couldn't preexchange
we couldn't preexchange
you couldn't preexchange
they couldn't preexchange 	I couldn't be preexchanging
you couldn't be preexchanging
he couldn't be preexchanging
we couldn't be preexchanging
you couldn't be preexchanging
they couldn't be preexchanging	I couldn't have preexchanged
you couldn't have preexchanged
he couldn't have preexchanged
we couldn't have preexchanged
you couldn't have preexchanged
they couldn't have preexchanged	I couldn't have been preexchanging
you couldn't have been preexchanging
he couldn't have been preexchanging
we couldn't have been preexchanging
you couldn't have been preexchanging
they couldn't have been preexchanging	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I preexchange?
could you preexchange?
could he preexchange?
could we preexchange?
could you preexchange?
could they preexchange? 	could I be preexchanging?
could you be preexchanging?
could he be preexchanging?
could we be preexchanging?
could you be preexchanging?
could they be preexchanging? 	could I have preexchanged?
could you have preexchanged?
could he have preexchanged?
could we have preexchanged?
could you have preexchanged?
could they have preexchanged? 	could I have been preexchanging?
could you have been preexchanging?
could he have been preexchanging?
could we have been preexchanging?
could you have been preexchanging?
could they have been preexchanging? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I preexchange?
couldn't you preexchange?
couldn't he preexchange?
couldn't we preexchange?
couldn't you preexchange?
couldn't they preexchange? 	couldn't I be preexchanging?
couldn't you be preexchanging?
couldn't he be preexchanging?
couldn't we be preexchanging?
couldn't you be preexchanging?
couldn't they be preexchanging? 	couldn't I have preexchanged?
couldn't you have preexchanged?
couldn't he have preexchanged?
couldn't we have preexchanged?
couldn't you have preexchanged?
couldn't they have preexchanged? 	couldn't I have been preexchanging?
couldn't you have been preexchanging?
couldn't he have been preexchanging?
couldn't we have been preexchanging?
couldn't you have been preexchanging?
couldn't they have been preexchanging?