Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could contend contend you could contend contend he could contend contend we could contend contend you could contend contend they could contend contend
V-ing form
I could be contend contending you could be contend contending he could be contend contending we could be contend contending you could be contend contending they could be contend contending
Perfect
I could have contend contended you could have contend contended he could have contend contended we could have contend contended you could have contend contended they could have contend contended
V-ing perfect
I could have been contend contending you could have been contend contending he could have been contend contending we could have been contend contending you could have been contend contending they could have been contend contending
Negation
Simple form
I could not contend contend you could not contend contend he could not contend contend we could not contend contend you could not contend contend they could not contend contend
V-ing form
I could not be contend contending you could not be contend contending he could not be contend contending we could not be contend contending you could not be contend contending they could not be contend contending
Perfect
I could not have contend contended you could not have contend contended he could not have contend contended we could not have contend contended you could not have contend contended they could not have contend contended
V-ing perfect
I could not have been contend contending you could not have been contend contending he could not have been contend contending we could not have been contend contending you could not have been contend contending they could not have been contend contending
Interrogative form
Simple form
could I contend contend? could you contend contend? could he contend contend? could we contend contend? could you contend contend? could they contend contend?
V-ing form
could I be contend contending? could you be contend contending? could he be contend contending? could we be contend contending? could you be contend contending? could they be contend contending?
Perfect
could I have contend contended? could you have contend contended? could he have contend contended? could we have contend contended? could you have contend contended? could they have contend contended?
V-ing perfect
could I have been contend contending? could you have been contend contending? could he have been contend contending? could we have been contend contending? could you have been contend contending? could they have been contend contending?
Interro-negative form
Simple form
could I not contend contend? could you not contend contend? could he not contend contend? could we not contend contend? could you not contend contend? could they not contend contend?
V-ing form
could I not be contend contending? could you not be contend contending? could he not be contend contending? could we not be contend contending? could you not be contend contending? could they not be contend contending?
Perfect
could I not have contend contended? could you not have contend contended? could he not have contend contended? could we not have contend contended? could you not have contend contended? could they not have contend contended?
V-ing perfect
could I not have been contend contending? could you not have been contend contending? could he not have been contend contending? could we not have been contend contending? could you not have been contend contending? could they not have been contend contending?