Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could express express you could express express she could express express we could express express you could express express they could express express
V-ing form
I could be express expressing you could be express expressing she could be express expressing we could be express expressing you could be express expressing they could be express expressing
Perfect
I could have express expressed you could have express expressed she could have express expressed we could have express expressed you could have express expressed they could have express expressed
V-ing perfect
I could have been express expressing you could have been express expressing she could have been express expressing we could have been express expressing you could have been express expressing they could have been express expressing
Negation
Simple form
I could not express express you could not express express she could not express express we could not express express you could not express express they could not express express
V-ing form
I could not be express expressing you could not be express expressing she could not be express expressing we could not be express expressing you could not be express expressing they could not be express expressing
Perfect
I could not have express expressed you could not have express expressed she could not have express expressed we could not have express expressed you could not have express expressed they could not have express expressed
V-ing perfect
I could not have been express expressing you could not have been express expressing she could not have been express expressing we could not have been express expressing you could not have been express expressing they could not have been express expressing
Interrogative form
Simple form
could I express express? could you express express? could she express express? could we express express? could you express express? could they express express?
V-ing form
could I be express expressing? could you be express expressing? could she be express expressing? could we be express expressing? could you be express expressing? could they be express expressing?
Perfect
could I have express expressed? could you have express expressed? could she have express expressed? could we have express expressed? could you have express expressed? could they have express expressed?
V-ing perfect
could I have been express expressing? could you have been express expressing? could she have been express expressing? could we have been express expressing? could you have been express expressing? could they have been express expressing?
Interro-negative form
Simple form
could I not express express? could you not express express? could she not express express? could we not express express? could you not express express? could they not express express?
V-ing form
could I not be express expressing? could you not be express expressing? could she not be express expressing? could we not be express expressing? could you not be express expressing? could they not be express expressing?
Perfect
could I not have express expressed? could you not have express expressed? could she not have express expressed? could we not have express expressed? could you not have express expressed? could they not have express expressed?
V-ing perfect
could I not have been express expressing? could you not have been express expressing? could she not have been express expressing? could we not have been express expressing? could you not have been express expressing? could they not have been express expressing?