English verb conjugation
COULD COUGH

Regular verb: cough - coughed - coughed

Affirmation

Simple form	V-ing form
I could cough you could cough he could cough we could cough you could cough they could cough	I could be coughing you could be coughing he could be coughing we could be coughing you could be coughing they could be coughing
Perfect	V-ing perfect
I could have coughed you could have coughed he could have coughed we could have coughed you could have coughed they could have coughed	I could have been coughing you could have been coughing he could have been coughing we could have been coughing you could have been coughing they could have been coughing

Negation

Simple form	V-ing form
I could not cough you could not cough he could not cough we could not cough you could not cough they could not cough	I could not be coughing you could not be coughing he could not be coughing we could not be coughing you could not be coughing they could not be coughing
Perfect	V-ing perfect
I could not have coughed you could not have coughed he could not have coughed we could not have coughed you could not have coughed they could not have coughed	I could not have been coughing you could not have been coughing he could not have been coughing we could not have been coughing you could not have been coughing they could not have been coughing

Interrogative form

Simple form	V-ing form
could I cough? could you cough? could he cough? could we cough? could you cough? could they cough?	could I be coughing? could you be coughing? could he be coughing? could we be coughing? could you be coughing? could they be coughing?
Perfect	V-ing perfect
could I have coughed? could you have coughed? could he have coughed? could we have coughed? could you have coughed? could they have coughed?	could I have been coughing? could you have been coughing? could he have been coughing? could we have been coughing? could you have been coughing? could they have been coughing?

Interro-negative form

Simple form	V-ing form
could I not cough? could you not cough? could he not cough? could we not cough? could you not cough? could they not cough?	could I not be coughing? could you not be coughing? could he not be coughing? could we not be coughing? could you not be coughing? could they not be coughing?
Perfect	V-ing perfect
could I not have coughed? could you not have coughed? could he not have coughed? could we not have coughed? could you not have coughed? could they not have coughed?	could I not have been coughing? could you not have been coughing? could he not have been coughing? could we not have been coughing? could you not have been coughing? could they not have been coughing?