can ripen
Regular verb: ripen - ripened- ripened

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

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot ripen
you cannot ripen
he cannot ripen
we cannot ripen
you cannot ripen
they cannot ripen 	I cannot be ripening
you cannot be ripening
he cannot be ripening
we cannot be ripening
you cannot be ripening
they cannot be ripening	I cannot have ripened
you cannot have ripened
he cannot have ripened
we cannot have ripened
you cannot have ripened
they cannot have ripened	I cannot have been ripening
you cannot have been ripening
he cannot have been ripening
we cannot have been ripening
you cannot have been ripening
they cannot have been ripening	

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

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not ripen?
can you not ripen?
can he not ripen?
can we not ripen?
can you not ripen?
can they not ripen? 	can I not be ripening?
can you not be ripening?
can he not be ripening?
can we not be ripening?
can you not be ripening?
can they not be ripening? 	can I not have ripened?
can you not have ripened?
can he not have ripened?
can we not have ripened?
can you not have ripened?
can they not have ripened? 	can I not have been ripening?
can you not have been ripening?
can he not have been ripening?
can we not have been ripening?
can you not have been ripening?
can they not have been ripening?