I could stress you could stress she could stress we could stress you could stress they could stress
V-ing form
I could be stressing you could be stressing she could be stressing we could be stressing you could be stressing they could be stressing
Perfect
I could have stressed you could have stressed she could have stressed we could have stressed you could have stressed they could have stressed
V-ing perfect
I could have been stressing you could have been stressing she could have been stressing we could have been stressing you could have been stressing they could have been stressing
Negation
Simple form
I couldn't stress you couldn't stress she couldn't stress we couldn't stress you couldn't stress they couldn't stress
V-ing form
I couldn't be stressing you couldn't be stressing she couldn't be stressing we couldn't be stressing you couldn't be stressing they couldn't be stressing
Perfect
I couldn't have stressed you couldn't have stressed she couldn't have stressed we couldn't have stressed you couldn't have stressed they couldn't have stressed
V-ing perfect
I couldn't have been stressing you couldn't have been stressing she couldn't have been stressing we couldn't have been stressing you couldn't have been stressing they couldn't have been stressing
Interrogative form
Simple form
could I stress? could you stress? could she stress? could we stress? could you stress? could they stress?
V-ing form
could I be stressing? could you be stressing? could she be stressing? could we be stressing? could you be stressing? could they be stressing?
Perfect
could I have stressed? could you have stressed? could she have stressed? could we have stressed? could you have stressed? could they have stressed?
V-ing perfect
could I have been stressing? could you have been stressing? could she have been stressing? could we have been stressing? could you have been stressing? could they have been stressing?
Interro-negative form
Simple form
couldn't I stress? couldn't you stress? couldn't she stress? couldn't we stress? couldn't you stress? couldn't they stress?
V-ing form
couldn't I be stressing? couldn't you be stressing? couldn't she be stressing? couldn't we be stressing? couldn't you be stressing? couldn't they be stressing?
Perfect
couldn't I have stressed? couldn't you have stressed? couldn't she have stressed? couldn't we have stressed? couldn't you have stressed? couldn't they have stressed?
V-ing perfect
couldn't I have been stressing? couldn't you have been stressing? couldn't she have been stressing? couldn't we have been stressing? couldn't you have been stressing? couldn't they have been stressing?