I could reharden you could reharden he could reharden we could reharden you could reharden they could reharden
V-ing form
I could be rehardening you could be rehardening he could be rehardening we could be rehardening you could be rehardening they could be rehardening
Perfect
I could have rehardened you could have rehardened he could have rehardened we could have rehardened you could have rehardened they could have rehardened
V-ing perfect
I could have been rehardening you could have been rehardening he could have been rehardening we could have been rehardening you could have been rehardening they could have been rehardening
Negation
Simple form
I could not reharden you could not reharden he could not reharden we could not reharden you could not reharden they could not reharden
V-ing form
I could not be rehardening you could not be rehardening he could not be rehardening we could not be rehardening you could not be rehardening they could not be rehardening
Perfect
I could not have rehardened you could not have rehardened he could not have rehardened we could not have rehardened you could not have rehardened they could not have rehardened
V-ing perfect
I could not have been rehardening you could not have been rehardening he could not have been rehardening we could not have been rehardening you could not have been rehardening they could not have been rehardening
Interrogative form
Simple form
could I reharden? could you reharden? could he reharden? could we reharden? could you reharden? could they reharden?
V-ing form
could I be rehardening? could you be rehardening? could he be rehardening? could we be rehardening? could you be rehardening? could they be rehardening?
Perfect
could I have rehardened? could you have rehardened? could he have rehardened? could we have rehardened? could you have rehardened? could they have rehardened?
V-ing perfect
could I have been rehardening? could you have been rehardening? could he have been rehardening? could we have been rehardening? could you have been rehardening? could they have been rehardening?
Interro-negative form
Simple form
could I not reharden? could you not reharden? could he not reharden? could we not reharden? could you not reharden? could they not reharden?
V-ing form
could I not be rehardening? could you not be rehardening? could he not be rehardening? could we not be rehardening? could you not be rehardening? could they not be rehardening?
Perfect
could I not have rehardened? could you not have rehardened? could he not have rehardened? could we not have rehardened? could you not have rehardened? could they not have rehardened?
V-ing perfect
could I not have been rehardening? could you not have been rehardening? could he not have been rehardening? could we not have been rehardening? could you not have been rehardening? could they not have been rehardening?