I can keen you can keen he can keen we can keen you can keen they can keen
V-ing form
I can be keening you can be keening he can be keening we can be keening you can be keening they can be keening
Perfect
I can have keened you can have keened he can have keened we can have keened you can have keened they can have keened
V-ing perfect
I can have been keening you can have been keening he can have been keening we can have been keening you can have been keening they can have been keening
Negation
Simple form
I can't keen you can't keen he can't keen we can't keen you can't keen they can't keen
V-ing form
I can't be keening you can't be keening he can't be keening we can't be keening you can't be keening they can't be keening
Perfect
I can't have keened you can't have keened he can't have keened we can't have keened you can't have keened they can't have keened
V-ing perfect
I can't have been keening you can't have been keening he can't have been keening we can't have been keening you can't have been keening they can't have been keening
Interrogative form
Simple form
can I keen? can you keen? can he keen? can we keen? can you keen? can they keen?
V-ing form
can I be keening? can you be keening? can he be keening? can we be keening? can you be keening? can they be keening?
Perfect
can I have keened? can you have keened? can he have keened? can we have keened? can you have keened? can they have keened?
V-ing perfect
can I have been keening? can you have been keening? can he have been keening? can we have been keening? can you have been keening? can they have been keening?
Interro-negative form
Simple form
can't I keen? can't you keen? can't he keen? can't we keen? can't you keen? can't they keen?
V-ing form
can't I be keening? can't you be keening? can't he be keening? can't we be keening? can't you be keening? can't they be keening?
Perfect
can't I have keened? can't you have keened? can't he have keened? can't we have keened? can't you have keened? can't they have keened?
V-ing perfect
can't I have been keening? can't you have been keening? can't he have been keening? can't we have been keening? can't you have been keening? can't they have been keening?