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