I can tub you can tub he can tub we can tub you can tub they can tub
V-ing form
I can be tubbing you can be tubbing he can be tubbing we can be tubbing you can be tubbing they can be tubbing
Perfect
I can have tubbed you can have tubbed he can have tubbed we can have tubbed you can have tubbed they can have tubbed
V-ing perfect
I can have been tubbing you can have been tubbing he can have been tubbing we can have been tubbing you can have been tubbing they can have been tubbing
Negation
Simple form
I can't tub you can't tub he can't tub we can't tub you can't tub they can't tub
V-ing form
I can't be tubbing you can't be tubbing he can't be tubbing we can't be tubbing you can't be tubbing they can't be tubbing
Perfect
I can't have tubbed you can't have tubbed he can't have tubbed we can't have tubbed you can't have tubbed they can't have tubbed
V-ing perfect
I can't have been tubbing you can't have been tubbing he can't have been tubbing we can't have been tubbing you can't have been tubbing they can't have been tubbing
Interrogative form
Simple form
can I tub? can you tub? can he tub? can we tub? can you tub? can they tub?
V-ing form
can I be tubbing? can you be tubbing? can he be tubbing? can we be tubbing? can you be tubbing? can they be tubbing?
Perfect
can I have tubbed? can you have tubbed? can he have tubbed? can we have tubbed? can you have tubbed? can they have tubbed?
V-ing perfect
can I have been tubbing? can you have been tubbing? can he have been tubbing? can we have been tubbing? can you have been tubbing? can they have been tubbing?
Interro-negative form
Simple form
can't I tub? can't you tub? can't he tub? can't we tub? can't you tub? can't they tub?
V-ing form
can't I be tubbing? can't you be tubbing? can't he be tubbing? can't we be tubbing? can't you be tubbing? can't they be tubbing?
Perfect
can't I have tubbed? can't you have tubbed? can't he have tubbed? can't we have tubbed? can't you have tubbed? can't they have tubbed?
V-ing perfect
can't I have been tubbing? can't you have been tubbing? can't he have been tubbing? can't we have been tubbing? can't you have been tubbing? can't they have been tubbing?