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