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