could ripen
Regular verb: ripen - ripened- ripened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could ripen
you could ripen
she could ripen
we could ripen
you could ripen
they could ripen 	I could be ripening
you could be ripening
she could be ripening
we could be ripening
you could be ripening
they could be ripening	I could have ripened
you could have ripened
she could have ripened
we could have ripened
you could have ripened
they could have ripened	I could have been ripening
you could have been ripening
she could have been ripening
we could have been ripening
you could have been ripening
they could have been ripening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't ripen
you couldn't ripen
she couldn't ripen
we couldn't ripen
you couldn't ripen
they couldn't ripen 	I couldn't be ripening
you couldn't be ripening
she couldn't be ripening
we couldn't be ripening
you couldn't be ripening
they couldn't be ripening	I couldn't have ripened
you couldn't have ripened
she couldn't have ripened
we couldn't have ripened
you couldn't have ripened
they couldn't have ripened	I couldn't have been ripening
you couldn't have been ripening
she couldn't have been ripening
we couldn't have been ripening
you couldn't have been ripening
they couldn't have been ripening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I ripen?
could you ripen?
could she ripen?
could we ripen?
could you ripen?
could they ripen? 	could I be ripening?
could you be ripening?
could she be ripening?
could we be ripening?
could you be ripening?
could they be ripening? 	could I have ripened?
could you have ripened?
could she have ripened?
could we have ripened?
could you have ripened?
could they have ripened? 	could I have been ripening?
could you have been ripening?
could she have been ripening?
could we have been ripening?
could you have been ripening?
could they have been ripening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I ripen?
couldn't you ripen?
couldn't she ripen?
couldn't we ripen?
couldn't you ripen?
couldn't they ripen? 	couldn't I be ripening?
couldn't you be ripening?
couldn't she be ripening?
couldn't we be ripening?
couldn't you be ripening?
couldn't they be ripening? 	couldn't I have ripened?
couldn't you have ripened?
couldn't she have ripened?
couldn't we have ripened?
couldn't you have ripened?
couldn't they have ripened? 	couldn't I have been ripening?
couldn't you have been ripening?
couldn't she have been ripening?
couldn't we have been ripening?
couldn't you have been ripening?
couldn't they have been ripening?