I can regress you can regress he can regress we can regress you can regress they can regress
V-ing form
I can be regressing you can be regressing he can be regressing we can be regressing you can be regressing they can be regressing
Perfect
I can have regressed you can have regressed he can have regressed we can have regressed you can have regressed they can have regressed
V-ing perfect
I can have been regressing you can have been regressing he can have been regressing we can have been regressing you can have been regressing they can have been regressing
Negation
Simple form
I cannot regress you cannot regress he cannot regress we cannot regress you cannot regress they cannot regress
V-ing form
I cannot be regressing you cannot be regressing he cannot be regressing we cannot be regressing you cannot be regressing they cannot be regressing
Perfect
I cannot have regressed you cannot have regressed he cannot have regressed we cannot have regressed you cannot have regressed they cannot have regressed
V-ing perfect
I cannot have been regressing you cannot have been regressing he cannot have been regressing we cannot have been regressing you cannot have been regressing they cannot have been regressing
Interrogative form
Simple form
can I regress? can you regress? can he regress? can we regress? can you regress? can they regress?
V-ing form
can I be regressing? can you be regressing? can he be regressing? can we be regressing? can you be regressing? can they be regressing?
Perfect
can I have regressed? can you have regressed? can he have regressed? can we have regressed? can you have regressed? can they have regressed?
V-ing perfect
can I have been regressing? can you have been regressing? can he have been regressing? can we have been regressing? can you have been regressing? can they have been regressing?
Interro-negative form
Simple form
can I not regress? can you not regress? can he not regress? can we not regress? can you not regress? can they not regress?
V-ing form
can I not be regressing? can you not be regressing? can he not be regressing? can we not be regressing? can you not be regressing? can they not be regressing?
Perfect
can I not have regressed? can you not have regressed? can he not have regressed? can we not have regressed? can you not have regressed? can they not have regressed?
V-ing perfect
can I not have been regressing? can you not have been regressing? can he not have been regressing? can we not have been regressing? can you not have been regressing? can they not have been regressing?