I can think you can think he can think we can think you can think they can think
V-ing form
I can be thinking you can be thinking he can be thinking we can be thinking you can be thinking they can be thinking
Perfect
I can have thought you can have thought he can have thought we can have thought you can have thought they can have thought
V-ing perfect
I can have been thinking you can have been thinking he can have been thinking we can have been thinking you can have been thinking they can have been thinking
Negation
Simple form
I can't think you can't think he can't think we can't think you can't think they can't think
V-ing form
I can't be thinking you can't be thinking he can't be thinking we can't be thinking you can't be thinking they can't be thinking
Perfect
I can't have thought you can't have thought he can't have thought we can't have thought you can't have thought they can't have thought
V-ing perfect
I can't have been thinking you can't have been thinking he can't have been thinking we can't have been thinking you can't have been thinking they can't have been thinking
Interrogative form
Simple form
can I think? can you think? can he think? can we think? can you think? can they think?
V-ing form
can I be thinking? can you be thinking? can he be thinking? can we be thinking? can you be thinking? can they be thinking?
Perfect
can I have thought? can you have thought? can he have thought? can we have thought? can you have thought? can they have thought?
V-ing perfect
can I have been thinking? can you have been thinking? can he have been thinking? can we have been thinking? can you have been thinking? can they have been thinking?
Interro-negative form
Simple form
can't I think? can't you think? can't he think? can't we think? can't you think? can't they think?
V-ing form
can't I be thinking? can't you be thinking? can't he be thinking? can't we be thinking? can't you be thinking? can't they be thinking?
Perfect
can't I have thought? can't you have thought? can't he have thought? can't we have thought? can't you have thought? can't they have thought?
V-ing perfect
can't I have been thinking? can't you have been thinking? can't he have been thinking? can't we have been thinking? can't you have been thinking? can't they have been thinking?