English verb conjugation
COULD REGRESS

Regular verb: regress - regressed - regressed

Affirmation

Simple form	V-ing form
I could regress you could regress he could regress we could regress you could regress they could regress	I could be regressing you could be regressing he could be regressing we could be regressing you could be regressing they could be regressing
Perfect	V-ing perfect
I could have regressed you could have regressed he could have regressed we could have regressed you could have regressed they could have regressed	I could have been regressing you could have been regressing he could have been regressing we could have been regressing you could have been regressing they could have been regressing

Negation

Simple form	V-ing form
I couldn't regress you couldn't regress he couldn't regress we couldn't regress you couldn't regress they couldn't regress	I couldn't be regressing you couldn't be regressing he couldn't be regressing we couldn't be regressing you couldn't be regressing they couldn't be regressing
Perfect	V-ing perfect
I couldn't have regressed you couldn't have regressed he couldn't have regressed we couldn't have regressed you couldn't have regressed they couldn't have regressed	I couldn't have been regressing you couldn't have been regressing he couldn't have been regressing we couldn't have been regressing you couldn't have been regressing they couldn't have been regressing

Interrogative form

Simple form	V-ing form
could I regress? could you regress? could he regress? could we regress? could you regress? could they regress?	could I be regressing? could you be regressing? could he be regressing? could we be regressing? could you be regressing? could they be regressing?
Perfect	V-ing perfect
could I have regressed? could you have regressed? could he have regressed? could we have regressed? could you have regressed? could they have regressed?	could I have been regressing? could you have been regressing? could he have been regressing? could we have been regressing? could you have been regressing? could they have been regressing?

Interro-negative form

Simple form	V-ing form
couldn't I regress? couldn't you regress? couldn't he regress? couldn't we regress? couldn't you regress? couldn't they regress?	couldn't I be regressing? couldn't you be regressing? couldn't he be regressing? couldn't we be regressing? couldn't you be regressing? couldn't they be regressing?
Perfect	V-ing perfect
couldn't I have regressed? couldn't you have regressed? couldn't he have regressed? couldn't we have regressed? couldn't you have regressed? couldn't they have regressed?	couldn't I have been regressing? couldn't you have been regressing? couldn't he have been regressing? couldn't we have been regressing? couldn't you have been regressing? couldn't they have been regressing?