I can fend you can fend he can fend we can fend you can fend they can fend
V-ing form
I can be fending you can be fending he can be fending we can be fending you can be fending they can be fending
Perfect
I can have fended you can have fended he 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 he can have been fending we can have been fending you can have been fending they can have been fending
Negation
Simple form
I can't fend you can't fend he can't fend we can't fend you can't fend they can't fend
V-ing form
I can't be fending you can't be fending he can't be fending we can't be fending you can't be fending they can't be fending
Perfect
I can't have fended you can't have fended he can't have fended we can't have fended you can't have fended they can't have fended
V-ing perfect
I can't have been fending you can't have been fending he can't have been fending we can't have been fending you can't have been fending they can't have been fending
Interrogative form
Simple form
can I fend? can you fend? can he fend? can we fend? can you fend? can they fend?
V-ing form
can I be fending? can you be fending? can he be fending? can we be fending? can you be fending? can they be fending?
Perfect
can I have fended? can you have fended? can he 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 he have been fending? can we have been fending? can you have been fending? can they have been fending?
Interro-negative form
Simple form
can't I fend? can't you fend? can't he fend? can't we fend? can't you fend? can't they fend?
V-ing form
can't I be fending? can't you be fending? can't he be fending? can't we be fending? can't you be fending? can't they be fending?
Perfect
can't I have fended? can't you have fended? can't he have fended? can't we have fended? can't you have fended? can't they have fended?
V-ing perfect
can't I have been fending? can't you have been fending? can't he have been fending? can't we have been fending? can't you have been fending? can't they have been fending?