I can sink you can sink he can sink we can sink you can sink they can sink
V-ing form
I can be sinking you can be sinking he can be sinking we can be sinking you can be sinking they can be sinking
Perfect
I can have sunk you can have sunk he can have sunk we can have sunk you can have sunk they can have sunk
V-ing perfect
I can have been sinking you can have been sinking he can have been sinking we can have been sinking you can have been sinking they can have been sinking
Negation
Simple form
I can't sink you can't sink he can't sink we can't sink you can't sink they can't sink
V-ing form
I can't be sinking you can't be sinking he can't be sinking we can't be sinking you can't be sinking they can't be sinking
Perfect
I can't have sunk you can't have sunk he can't have sunk we can't have sunk you can't have sunk they can't have sunk
V-ing perfect
I can't have been sinking you can't have been sinking he can't have been sinking we can't have been sinking you can't have been sinking they can't have been sinking
Interrogative form
Simple form
can I sink? can you sink? can he sink? can we sink? can you sink? can they sink?
V-ing form
can I be sinking? can you be sinking? can he be sinking? can we be sinking? can you be sinking? can they be sinking?
Perfect
can I have sunk? can you have sunk? can he have sunk? can we have sunk? can you have sunk? can they have sunk?
V-ing perfect
can I have been sinking? can you have been sinking? can he have been sinking? can we have been sinking? can you have been sinking? can they have been sinking?
Interro-negative form
Simple form
can't I sink? can't you sink? can't he sink? can't we sink? can't you sink? can't they sink?
V-ing form
can't I be sinking? can't you be sinking? can't he be sinking? can't we be sinking? can't you be sinking? can't they be sinking?
Perfect
can't I have sunk? can't you have sunk? can't he have sunk? can't we have sunk? can't you have sunk? can't they have sunk?
V-ing perfect
can't I have been sinking? can't you have been sinking? can't he have been sinking? can't we have been sinking? can't you have been sinking? can't they have been sinking?