I could prefertilise you could prefertilise he could prefertilise we could prefertilise you could prefertilise they could prefertilise
V-ing form
I could be prefertilising you could be prefertilising he could be prefertilising we could be prefertilising you could be prefertilising they could be prefertilising
Perfect
I could have prefertilised you could have prefertilised he could have prefertilised we could have prefertilised you could have prefertilised they could have prefertilised
V-ing perfect
I could have been prefertilising you could have been prefertilising he could have been prefertilising we could have been prefertilising you could have been prefertilising they could have been prefertilising
Negation
Simple form
I could not prefertilise you could not prefertilise he could not prefertilise we could not prefertilise you could not prefertilise they could not prefertilise
V-ing form
I could not be prefertilising you could not be prefertilising he could not be prefertilising we could not be prefertilising you could not be prefertilising they could not be prefertilising
Perfect
I could not have prefertilised you could not have prefertilised he could not have prefertilised we could not have prefertilised you could not have prefertilised they could not have prefertilised
V-ing perfect
I could not have been prefertilising you could not have been prefertilising he could not have been prefertilising we could not have been prefertilising you could not have been prefertilising they could not have been prefertilising
Interrogative form
Simple form
could I prefertilise? could you prefertilise? could he prefertilise? could we prefertilise? could you prefertilise? could they prefertilise?
V-ing form
could I be prefertilising? could you be prefertilising? could he be prefertilising? could we be prefertilising? could you be prefertilising? could they be prefertilising?
Perfect
could I have prefertilised? could you have prefertilised? could he have prefertilised? could we have prefertilised? could you have prefertilised? could they have prefertilised?
V-ing perfect
could I have been prefertilising? could you have been prefertilising? could he have been prefertilising? could we have been prefertilising? could you have been prefertilising? could they have been prefertilising?
Interro-negative form
Simple form
could I not prefertilise? could you not prefertilise? could he not prefertilise? could we not prefertilise? could you not prefertilise? could they not prefertilise?
V-ing form
could I not be prefertilising? could you not be prefertilising? could he not be prefertilising? could we not be prefertilising? could you not be prefertilising? could they not be prefertilising?
Perfect
could I not have prefertilised? could you not have prefertilised? could he not have prefertilised? could we not have prefertilised? could you not have prefertilised? could they not have prefertilised?
V-ing perfect
could I not have been prefertilising? could you not have been prefertilising? could he not have been prefertilising? could we not have been prefertilising? could you not have been prefertilising? could they not have been prefertilising?