I can ripen you can ripen he can ripen we can ripen you can ripen they can ripen
V-ing form
I can be ripening you can be ripening he can be ripening we can be ripening you can be ripening they can be ripening
Perfect
I can have ripened you can have ripened he can have ripened we can have ripened you can have ripened they can have ripened
V-ing perfect
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
I can't ripen you can't ripen he can't ripen we can't ripen you can't ripen they can't ripen
V-ing form
I can't be ripening you can't be ripening he can't be ripening we can't be ripening you can't be ripening they can't be ripening
Perfect
I can't have ripened you can't have ripened he can't have ripened we can't have ripened you can't have ripened they can't have ripened
V-ing perfect
I can't have been ripening you can't have been ripening he can't have been ripening we can't have been ripening you can't have been ripening they can't have been ripening
Interrogative form
Simple form
can I ripen? can you ripen? can he ripen? can we ripen? can you ripen? can they ripen?
V-ing form
can I be ripening? can you be ripening? can he be ripening? can we be ripening? can you be ripening? can they be ripening?
Perfect
can I have ripened? can you have ripened? can he have ripened? can we have ripened? can you have ripened? can they have ripened?
V-ing perfect
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
can't I ripen? can't you ripen? can't he ripen? can't we ripen? can't you ripen? can't they ripen?
V-ing form
can't I be ripening? can't you be ripening? can't he be ripening? can't we be ripening? can't you be ripening? can't they be ripening?
Perfect
can't I have ripened? can't you have ripened? can't he have ripened? can't we have ripened? can't you have ripened? can't they have ripened?
V-ing perfect
can't I have been ripening? can't you have been ripening? can't he have been ripening? can't we have been ripening? can't you have been ripening? can't they have been ripening?