I can tub you can tub she can tub we can tub you can tub they can tub
V-ing form
I can be tubbing you can be tubbing she can be tubbing we can be tubbing you can be tubbing they can be tubbing
Perfect
I can have tubbed you can have tubbed she 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 she 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 she 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 she 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 she 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 she 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 she tub? can we tub? can you tub? can they tub?
V-ing form
can I be tubbing? can you be tubbing? can she be tubbing? can we be tubbing? can you be tubbing? can they be tubbing?
Perfect
can I have tubbed? can you have tubbed? can she 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 she 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 she 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 she 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 she 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 she have been tubbing? can't we have been tubbing? can't you have been tubbing? can't they have been tubbing?