could greaten
Regular verb: greaten - greatened- greatened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could greaten
you could greaten
he could greaten
we could greaten
you could greaten
they could greaten 	I could be greatening
you could be greatening
he could be greatening
we could be greatening
you could be greatening
they could be greatening	I could have greatened
you could have greatened
he could have greatened
we could have greatened
you could have greatened
they could have greatened	I could have been greatening
you could have been greatening
he could have been greatening
we could have been greatening
you could have been greatening
they could have been greatening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not greaten
you could not greaten
he could not greaten
we could not greaten
you could not greaten
they could not greaten 	I could not be greatening
you could not be greatening
he could not be greatening
we could not be greatening
you could not be greatening
they could not be greatening	I could not have greatened
you could not have greatened
he could not have greatened
we could not have greatened
you could not have greatened
they could not have greatened	I could not have been greatening
you could not have been greatening
he could not have been greatening
we could not have been greatening
you could not have been greatening
they could not have been greatening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I greaten?
could you greaten?
could he greaten?
could we greaten?
could you greaten?
could they greaten? 	could I be greatening?
could you be greatening?
could he be greatening?
could we be greatening?
could you be greatening?
could they be greatening? 	could I have greatened?
could you have greatened?
could he have greatened?
could we have greatened?
could you have greatened?
could they have greatened? 	could I have been greatening?
could you have been greatening?
could he have been greatening?
could we have been greatening?
could you have been greatening?
could they have been greatening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not greaten?
could you not greaten?
could he not greaten?
could we not greaten?
could you not greaten?
could they not greaten? 	could I not be greatening?
could you not be greatening?
could he not be greatening?
could we not be greatening?
could you not be greatening?
could they not be greatening? 	could I not have greatened?
could you not have greatened?
could he not have greatened?
could we not have greatened?
could you not have greatened?
could they not have greatened? 	could I not have been greatening?
could you not have been greatening?
could he not have been greatening?
could we not have been greatening?
could you not have been greatening?
could they not have been greatening?