I can chat you can chat he can chat we can chat you can chat they can chat
V-ing form
I can be chatting you can be chatting he can be chatting we can be chatting you can be chatting they can be chatting
Perfect
I can have chatted you can have chatted he can have chatted we can have chatted you can have chatted they can have chatted
V-ing perfect
I can have been chatting you can have been chatting he can have been chatting we can have been chatting you can have been chatting they can have been chatting
Negation
Simple form
I can't chat you can't chat he can't chat we can't chat you can't chat they can't chat
V-ing form
I can't be chatting you can't be chatting he can't be chatting we can't be chatting you can't be chatting they can't be chatting
Perfect
I can't have chatted you can't have chatted he can't have chatted we can't have chatted you can't have chatted they can't have chatted
V-ing perfect
I can't have been chatting you can't have been chatting he can't have been chatting we can't have been chatting you can't have been chatting they can't have been chatting
Interrogative form
Simple form
can I chat? can you chat? can he chat? can we chat? can you chat? can they chat?
V-ing form
can I be chatting? can you be chatting? can he be chatting? can we be chatting? can you be chatting? can they be chatting?
Perfect
can I have chatted? can you have chatted? can he have chatted? can we have chatted? can you have chatted? can they have chatted?
V-ing perfect
can I have been chatting? can you have been chatting? can he have been chatting? can we have been chatting? can you have been chatting? can they have been chatting?
Interro-negative form
Simple form
can't I chat? can't you chat? can't he chat? can't we chat? can't you chat? can't they chat?
V-ing form
can't I be chatting? can't you be chatting? can't he be chatting? can't we be chatting? can't you be chatting? can't they be chatting?
Perfect
can't I have chatted? can't you have chatted? can't he have chatted? can't we have chatted? can't you have chatted? can't they have chatted?
V-ing perfect
can't I have been chatting? can't you have been chatting? can't he have been chatting? can't we have been chatting? can't you have been chatting? can't they have been chatting?