I could fend you could fend she could fend we could fend you could fend they could fend
V-ing form
I could be fending you could be fending she could be fending we could be fending you could be fending they could be fending
Perfect
I could have fended you could have fended she 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 she 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 she 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 she 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 she 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 she 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 she fend? could we fend? could you fend? could they fend?
V-ing form
could I be fending? could you be fending? could she be fending? could we be fending? could you be fending? could they be fending?
Perfect
could I have fended? could you have fended? could she 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 she 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 she 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 she 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 she 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 she have been fending? couldn't we have been fending? couldn't you have been fending? couldn't they have been fending?