could prestress
Regular verb: prestress - prestressed- prestressed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could prestress
you could prestress
he could prestress
we could prestress
you could prestress
they could prestress 	I could be prestressing
you could be prestressing
he could be prestressing
we could be prestressing
you could be prestressing
they could be prestressing	I could have prestressed
you could have prestressed
he could have prestressed
we could have prestressed
you could have prestressed
they could have prestressed	I could have been prestressing
you could have been prestressing
he could have been prestressing
we could have been prestressing
you could have been prestressing
they could have been prestressing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't prestress
you couldn't prestress
he couldn't prestress
we couldn't prestress
you couldn't prestress
they couldn't prestress 	I couldn't be prestressing
you couldn't be prestressing
he couldn't be prestressing
we couldn't be prestressing
you couldn't be prestressing
they couldn't be prestressing	I couldn't have prestressed
you couldn't have prestressed
he couldn't have prestressed
we couldn't have prestressed
you couldn't have prestressed
they couldn't have prestressed	I couldn't have been prestressing
you couldn't have been prestressing
he couldn't have been prestressing
we couldn't have been prestressing
you couldn't have been prestressing
they couldn't have been prestressing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I prestress?
could you prestress?
could he prestress?
could we prestress?
could you prestress?
could they prestress? 	could I be prestressing?
could you be prestressing?
could he be prestressing?
could we be prestressing?
could you be prestressing?
could they be prestressing? 	could I have prestressed?
could you have prestressed?
could he have prestressed?
could we have prestressed?
could you have prestressed?
could they have prestressed? 	could I have been prestressing?
could you have been prestressing?
could he have been prestressing?
could we have been prestressing?
could you have been prestressing?
could they have been prestressing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I prestress?
couldn't you prestress?
couldn't he prestress?
couldn't we prestress?
couldn't you prestress?
couldn't they prestress? 	couldn't I be prestressing?
couldn't you be prestressing?
couldn't he be prestressing?
couldn't we be prestressing?
couldn't you be prestressing?
couldn't they be prestressing? 	couldn't I have prestressed?
couldn't you have prestressed?
couldn't he have prestressed?
couldn't we have prestressed?
couldn't you have prestressed?
couldn't they have prestressed? 	couldn't I have been prestressing?
couldn't you have been prestressing?
couldn't he have been prestressing?
couldn't we have been prestressing?
couldn't you have been prestressing?
couldn't they have been prestressing?