English verb conjugation
CAN RUB

Regular verb: rub - rubbed - rubbed

Affirmation

Simple form	V-ing form
I can rub you can rub he can rub we can rub you can rub they can rub	I can be rubbing you can be rubbing he can be rubbing we can be rubbing you can be rubbing they can be rubbing
Perfect	V-ing perfect
I can have rubbed you can have rubbed he can have rubbed we can have rubbed you can have rubbed they can have rubbed	I can have been rubbing you can have been rubbing he can have been rubbing we can have been rubbing you can have been rubbing they can have been rubbing

Negation

Simple form	V-ing form
I can't rub you can't rub he can't rub we can't rub you can't rub they can't rub	I can't be rubbing you can't be rubbing he can't be rubbing we can't be rubbing you can't be rubbing they can't be rubbing
Perfect	V-ing perfect
I can't have rubbed you can't have rubbed he can't have rubbed we can't have rubbed you can't have rubbed they can't have rubbed	I can't have been rubbing you can't have been rubbing he can't have been rubbing we can't have been rubbing you can't have been rubbing they can't have been rubbing

Interrogative form

Simple form	V-ing form
can I rub? can you rub? can he rub? can we rub? can you rub? can they rub?	can I be rubbing? can you be rubbing? can he be rubbing? can we be rubbing? can you be rubbing? can they be rubbing?
Perfect	V-ing perfect
can I have rubbed? can you have rubbed? can he have rubbed? can we have rubbed? can you have rubbed? can they have rubbed?	can I have been rubbing? can you have been rubbing? can he have been rubbing? can we have been rubbing? can you have been rubbing? can they have been rubbing?

Interro-negative form

Simple form	V-ing form
can't I rub? can't you rub? can't he rub? can't we rub? can't you rub? can't they rub?	can't I be rubbing? can't you be rubbing? can't he be rubbing? can't we be rubbing? can't you be rubbing? can't they be rubbing?
Perfect	V-ing perfect
can't I have rubbed? can't you have rubbed? can't he have rubbed? can't we have rubbed? can't you have rubbed? can't they have rubbed?	can't I have been rubbing? can't you have been rubbing? can't he have been rubbing? can't we have been rubbing? can't you have been rubbing? can't they have been rubbing?