I can comb you can comb she can comb we can comb you can comb they can comb
V-ing form
I can be combing you can be combing she can be combing we can be combing you can be combing they can be combing
Perfect
I can have combed you can have combed she can have combed we can have combed you can have combed they can have combed
V-ing perfect
I can have been combing you can have been combing she can have been combing we can have been combing you can have been combing they can have been combing
Negation
Simple form
I cannot comb you cannot comb she cannot comb we cannot comb you cannot comb they cannot comb
V-ing form
I cannot be combing you cannot be combing she cannot be combing we cannot be combing you cannot be combing they cannot be combing
Perfect
I cannot have combed you cannot have combed she cannot have combed we cannot have combed you cannot have combed they cannot have combed
V-ing perfect
I cannot have been combing you cannot have been combing she cannot have been combing we cannot have been combing you cannot have been combing they cannot have been combing
Interrogative form
Simple form
can I comb? can you comb? can she comb? can we comb? can you comb? can they comb?
V-ing form
can I be combing? can you be combing? can she be combing? can we be combing? can you be combing? can they be combing?
Perfect
can I have combed? can you have combed? can she have combed? can we have combed? can you have combed? can they have combed?
V-ing perfect
can I have been combing? can you have been combing? can she have been combing? can we have been combing? can you have been combing? can they have been combing?
Interro-negative form
Simple form
can I not comb? can you not comb? can she not comb? can we not comb? can you not comb? can they not comb?
V-ing form
can I not be combing? can you not be combing? can she not be combing? can we not be combing? can you not be combing? can they not be combing?
Perfect
can I not have combed? can you not have combed? can she not have combed? can we not have combed? can you not have combed? can they not have combed?
V-ing perfect
can I not have been combing? can you not have been combing? can she not have been combing? can we not have been combing? can you not have been combing? can they not have been combing?