I could winterise you could winterise he could winterise we could winterise you could winterise they could winterise
V-ing form
I could be winterising you could be winterising he could be winterising we could be winterising you could be winterising they could be winterising
Perfect
I could have winterised you could have winterised he could have winterised we could have winterised you could have winterised they could have winterised
V-ing perfect
I could have been winterising you could have been winterising he could have been winterising we could have been winterising you could have been winterising they could have been winterising
Negation
Simple form
I could not winterise you could not winterise he could not winterise we could not winterise you could not winterise they could not winterise
V-ing form
I could not be winterising you could not be winterising he could not be winterising we could not be winterising you could not be winterising they could not be winterising
Perfect
I could not have winterised you could not have winterised he could not have winterised we could not have winterised you could not have winterised they could not have winterised
V-ing perfect
I could not have been winterising you could not have been winterising he could not have been winterising we could not have been winterising you could not have been winterising they could not have been winterising
Interrogative form
Simple form
could I winterise? could you winterise? could he winterise? could we winterise? could you winterise? could they winterise?
V-ing form
could I be winterising? could you be winterising? could he be winterising? could we be winterising? could you be winterising? could they be winterising?
Perfect
could I have winterised? could you have winterised? could he have winterised? could we have winterised? could you have winterised? could they have winterised?
V-ing perfect
could I have been winterising? could you have been winterising? could he have been winterising? could we have been winterising? could you have been winterising? could they have been winterising?
Interro-negative form
Simple form
could I not winterise? could you not winterise? could he not winterise? could we not winterise? could you not winterise? could they not winterise?
V-ing form
could I not be winterising? could you not be winterising? could he not be winterising? could we not be winterising? could you not be winterising? could they not be winterising?
Perfect
could I not have winterised? could you not have winterised? could he not have winterised? could we not have winterised? could you not have winterised? could they not have winterised?
V-ing perfect
could I not have been winterising? could you not have been winterising? could he not have been winterising? could we not have been winterising? could you not have been winterising? could they not have been winterising?