I could presterilise you could presterilise she could presterilise we could presterilise you could presterilise they could presterilise
V-ing form
I could be presterilising you could be presterilising she could be presterilising we could be presterilising you could be presterilising they could be presterilising
Perfect
I could have presterilised you could have presterilised she could have presterilised we could have presterilised you could have presterilised they could have presterilised
V-ing perfect
I could have been presterilising you could have been presterilising she could have been presterilising we could have been presterilising you could have been presterilising they could have been presterilising
Negation
Simple form
I could not presterilise you could not presterilise she could not presterilise we could not presterilise you could not presterilise they could not presterilise
V-ing form
I could not be presterilising you could not be presterilising she could not be presterilising we could not be presterilising you could not be presterilising they could not be presterilising
Perfect
I could not have presterilised you could not have presterilised she could not have presterilised we could not have presterilised you could not have presterilised they could not have presterilised
V-ing perfect
I could not have been presterilising you could not have been presterilising she could not have been presterilising we could not have been presterilising you could not have been presterilising they could not have been presterilising
Interrogative form
Simple form
could I presterilise? could you presterilise? could she presterilise? could we presterilise? could you presterilise? could they presterilise?
V-ing form
could I be presterilising? could you be presterilising? could she be presterilising? could we be presterilising? could you be presterilising? could they be presterilising?
Perfect
could I have presterilised? could you have presterilised? could she have presterilised? could we have presterilised? could you have presterilised? could they have presterilised?
V-ing perfect
could I have been presterilising? could you have been presterilising? could she have been presterilising? could we have been presterilising? could you have been presterilising? could they have been presterilising?
Interro-negative form
Simple form
could I not presterilise? could you not presterilise? could she not presterilise? could we not presterilise? could you not presterilise? could they not presterilise?
V-ing form
could I not be presterilising? could you not be presterilising? could she not be presterilising? could we not be presterilising? could you not be presterilising? could they not be presterilising?
Perfect
could I not have presterilised? could you not have presterilised? could she not have presterilised? could we not have presterilised? could you not have presterilised? could they not have presterilised?
V-ing perfect
could I not have been presterilising? could you not have been presterilising? could she not have been presterilising? could we not have been presterilising? could you not have been presterilising? could they not have been presterilising?