I could polymerise you could polymerise he could polymerise we could polymerise you could polymerise they could polymerise
V-ing form
I could be polymerising you could be polymerising he could be polymerising we could be polymerising you could be polymerising they could be polymerising
Perfect
I could have polymerised you could have polymerised he could have polymerised we could have polymerised you could have polymerised they could have polymerised
V-ing perfect
I could have been polymerising you could have been polymerising he could have been polymerising we could have been polymerising you could have been polymerising they could have been polymerising
Negation
Simple form
I couldn't polymerise you couldn't polymerise he couldn't polymerise we couldn't polymerise you couldn't polymerise they couldn't polymerise
V-ing form
I couldn't be polymerising you couldn't be polymerising he couldn't be polymerising we couldn't be polymerising you couldn't be polymerising they couldn't be polymerising
Perfect
I couldn't have polymerised you couldn't have polymerised he couldn't have polymerised we couldn't have polymerised you couldn't have polymerised they couldn't have polymerised
V-ing perfect
I couldn't have been polymerising you couldn't have been polymerising he couldn't have been polymerising we couldn't have been polymerising you couldn't have been polymerising they couldn't have been polymerising
Interrogative form
Simple form
could I polymerise? could you polymerise? could he polymerise? could we polymerise? could you polymerise? could they polymerise?
V-ing form
could I be polymerising? could you be polymerising? could he be polymerising? could we be polymerising? could you be polymerising? could they be polymerising?
Perfect
could I have polymerised? could you have polymerised? could he have polymerised? could we have polymerised? could you have polymerised? could they have polymerised?
V-ing perfect
could I have been polymerising? could you have been polymerising? could he have been polymerising? could we have been polymerising? could you have been polymerising? could they have been polymerising?
Interro-negative form
Simple form
couldn't I polymerise? couldn't you polymerise? couldn't he polymerise? couldn't we polymerise? couldn't you polymerise? couldn't they polymerise?
V-ing form
couldn't I be polymerising? couldn't you be polymerising? couldn't he be polymerising? couldn't we be polymerising? couldn't you be polymerising? couldn't they be polymerising?
Perfect
couldn't I have polymerised? couldn't you have polymerised? couldn't he have polymerised? couldn't we have polymerised? couldn't you have polymerised? couldn't they have polymerised?
V-ing perfect
couldn't I have been polymerising? couldn't you have been polymerising? couldn't he have been polymerising? couldn't we have been polymerising? couldn't you have been polymerising? couldn't they have been polymerising?