I could knit you could knit he could knit we could knit you could knit they could knit
V-ing form
I could be knitting you could be knitting he could be knitting we could be knitting you could be knitting they could be knitting
Perfect
I could have knitted, knit you could have knitted, knit he could have knitted, knit we could have knitted, knit you could have knitted, knit they could have knitted, knit
V-ing perfect
I could have been knitting you could have been knitting he could have been knitting we could have been knitting you could have been knitting they could have been knitting
Negation
Simple form
I couldn't knit you couldn't knit he couldn't knit we couldn't knit you couldn't knit they couldn't knit
V-ing form
I couldn't be knitting you couldn't be knitting he couldn't be knitting we couldn't be knitting you couldn't be knitting they couldn't be knitting
Perfect
I couldn't have knitted, knit you couldn't have knitted, knit he couldn't have knitted, knit we couldn't have knitted, knit you couldn't have knitted, knit they couldn't have knitted, knit
V-ing perfect
I couldn't have been knitting you couldn't have been knitting he couldn't have been knitting we couldn't have been knitting you couldn't have been knitting they couldn't have been knitting
Interrogative form
Simple form
could I knit? could you knit? could he knit? could we knit? could you knit? could they knit?
V-ing form
could I be knitting? could you be knitting? could he be knitting? could we be knitting? could you be knitting? could they be knitting?
Perfect
could I have knitted, knit? could you have knitted, knit? could he have knitted, knit? could we have knitted, knit? could you have knitted, knit? could they have knitted, knit?
V-ing perfect
could I have been knitting? could you have been knitting? could he have been knitting? could we have been knitting? could you have been knitting? could they have been knitting?
Interro-negative form
Simple form
couldn't I knit? couldn't you knit? couldn't he knit? couldn't we knit? couldn't you knit? couldn't they knit?
V-ing form
couldn't I be knitting? couldn't you be knitting? couldn't he be knitting? couldn't we be knitting? couldn't you be knitting? couldn't they be knitting?
Perfect
couldn't I have knitted, knit? couldn't you have knitted, knit? couldn't he have knitted, knit? couldn't we have knitted, knit? couldn't you have knitted, knit? couldn't they have knitted, knit?
V-ing perfect
couldn't I have been knitting? couldn't you have been knitting? couldn't he have been knitting? couldn't we have been knitting? couldn't you have been knitting? couldn't they have been knitting?