I can fend you can fend she can fend we can fend you can fend they can fend
V-ing form
I can be fending you can be fending she can be fending we can be fending you can be fending they can be fending
Perfect
I can have fended you can have fended she can have fended we can have fended you can have fended they can have fended
V-ing perfect
I can have been fending you can have been fending she can have been fending we can have been fending you can have been fending they can have been fending
Negation
Simple form
I cannot fend you cannot fend she cannot fend we cannot fend you cannot fend they cannot fend
V-ing form
I cannot be fending you cannot be fending she cannot be fending we cannot be fending you cannot be fending they cannot be fending
Perfect
I cannot have fended you cannot have fended she cannot have fended we cannot have fended you cannot have fended they cannot have fended
V-ing perfect
I cannot have been fending you cannot have been fending she cannot have been fending we cannot have been fending you cannot have been fending they cannot have been fending
Interrogative form
Simple form
can I fend? can you fend? can she fend? can we fend? can you fend? can they fend?
V-ing form
can I be fending? can you be fending? can she be fending? can we be fending? can you be fending? can they be fending?
Perfect
can I have fended? can you have fended? can she have fended? can we have fended? can you have fended? can they have fended?
V-ing perfect
can I have been fending? can you have been fending? can she have been fending? can we have been fending? can you have been fending? can they have been fending?
Interro-negative form
Simple form
can I not fend? can you not fend? can she not fend? can we not fend? can you not fend? can they not fend?
V-ing form
can I not be fending? can you not be fending? can she not be fending? can we not be fending? can you not be fending? can they not be fending?
Perfect
can I not have fended? can you not have fended? can she not have fended? can we not have fended? can you not have fended? can they not have fended?
V-ing perfect
can I not have been fending? can you not have been fending? can she not have been fending? can we not have been fending? can you not have been fending? can they not have been fending?