I could seek you could seek he could seek we could seek you could seek they could seek
V-ing form
I could be seeking you could be seeking he could be seeking we could be seeking you could be seeking they could be seeking
Perfect
I could have sought you could have sought he could have sought we could have sought you could have sought they could have sought
V-ing perfect
I could have been seeking you could have been seeking he could have been seeking we could have been seeking you could have been seeking they could have been seeking
Negation
Simple form
I could not seek you could not seek he could not seek we could not seek you could not seek they could not seek
V-ing form
I could not be seeking you could not be seeking he could not be seeking we could not be seeking you could not be seeking they could not be seeking
Perfect
I could not have sought you could not have sought he could not have sought we could not have sought you could not have sought they could not have sought
V-ing perfect
I could not have been seeking you could not have been seeking he could not have been seeking we could not have been seeking you could not have been seeking they could not have been seeking
Interrogative form
Simple form
could I seek? could you seek? could he seek? could we seek? could you seek? could they seek?
V-ing form
could I be seeking? could you be seeking? could he be seeking? could we be seeking? could you be seeking? could they be seeking?
Perfect
could I have sought? could you have sought? could he have sought? could we have sought? could you have sought? could they have sought?
V-ing perfect
could I have been seeking? could you have been seeking? could he have been seeking? could we have been seeking? could you have been seeking? could they have been seeking?
Interro-negative form
Simple form
could I not seek? could you not seek? could he not seek? could we not seek? could you not seek? could they not seek?
V-ing form
could I not be seeking? could you not be seeking? could he not be seeking? could we not be seeking? could you not be seeking? could they not be seeking?
Perfect
could I not have sought? could you not have sought? could he not have sought? could we not have sought? could you not have sought? could they not have sought?
V-ing perfect
could I not have been seeking? could you not have been seeking? could he not have been seeking? could we not have been seeking? could you not have been seeking? could they not have been seeking?