I can keen you can keen she can keen we can keen you can keen they can keen
V-ing form
I can be keening you can be keening she can be keening we can be keening you can be keening they can be keening
Perfect
I can have keened you can have keened she 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 she 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 she 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 she 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 she 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 she 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 she keen? can we keen? can you keen? can they keen?
V-ing form
can I be keening? can you be keening? can she be keening? can we be keening? can you be keening? can they be keening?
Perfect
can I have keened? can you have keened? can she 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 she 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 she 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 she 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 she 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 she have been keening? can't we have been keening? can't you have been keening? can't they have been keening?