I could materialise you could materialise he could materialise we could materialise you could materialise they could materialise
V-ing form
I could be materialising you could be materialising he could be materialising we could be materialising you could be materialising they could be materialising
Perfect
I could have materialised you could have materialised he could have materialised we could have materialised you could have materialised they could have materialised
V-ing perfect
I could have been materialising you could have been materialising he could have been materialising we could have been materialising you could have been materialising they could have been materialising
Negation
Simple form
I could not materialise you could not materialise he could not materialise we could not materialise you could not materialise they could not materialise
V-ing form
I could not be materialising you could not be materialising he could not be materialising we could not be materialising you could not be materialising they could not be materialising
Perfect
I could not have materialised you could not have materialised he could not have materialised we could not have materialised you could not have materialised they could not have materialised
V-ing perfect
I could not have been materialising you could not have been materialising he could not have been materialising we could not have been materialising you could not have been materialising they could not have been materialising
Interrogative form
Simple form
could I materialise? could you materialise? could he materialise? could we materialise? could you materialise? could they materialise?
V-ing form
could I be materialising? could you be materialising? could he be materialising? could we be materialising? could you be materialising? could they be materialising?
Perfect
could I have materialised? could you have materialised? could he have materialised? could we have materialised? could you have materialised? could they have materialised?
V-ing perfect
could I have been materialising? could you have been materialising? could he have been materialising? could we have been materialising? could you have been materialising? could they have been materialising?
Interro-negative form
Simple form
could I not materialise? could you not materialise? could he not materialise? could we not materialise? could you not materialise? could they not materialise?
V-ing form
could I not be materialising? could you not be materialising? could he not be materialising? could we not be materialising? could you not be materialising? could they not be materialising?
Perfect
could I not have materialised? could you not have materialised? could he not have materialised? could we not have materialised? could you not have materialised? could they not have materialised?
V-ing perfect
could I not have been materialising? could you not have been materialising? could he not have been materialising? could we not have been materialising? could you not have been materialising? could they not have been materialising?