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