English verb conjugation
COULD COUNTERSIGN

Regular verb: countersign - countersigned - countersigned

Affirmation

Simple form	V-ing form
I could countersign you could countersign she could countersign we could countersign you could countersign they could countersign	I could be countersigning you could be countersigning she could be countersigning we could be countersigning you could be countersigning they could be countersigning
Perfect	V-ing perfect
I could have countersigned you could have countersigned she could have countersigned we could have countersigned you could have countersigned they could have countersigned	I could have been countersigning you could have been countersigning she could have been countersigning we could have been countersigning you could have been countersigning they could have been countersigning

Negation

Simple form	V-ing form
I couldn't countersign you couldn't countersign she couldn't countersign we couldn't countersign you couldn't countersign they couldn't countersign	I couldn't be countersigning you couldn't be countersigning she couldn't be countersigning we couldn't be countersigning you couldn't be countersigning they couldn't be countersigning
Perfect	V-ing perfect
I couldn't have countersigned you couldn't have countersigned she couldn't have countersigned we couldn't have countersigned you couldn't have countersigned they couldn't have countersigned	I couldn't have been countersigning you couldn't have been countersigning she couldn't have been countersigning we couldn't have been countersigning you couldn't have been countersigning they couldn't have been countersigning

Interrogative form

Simple form	V-ing form
could I countersign? could you countersign? could she countersign? could we countersign? could you countersign? could they countersign?	could I be countersigning? could you be countersigning? could she be countersigning? could we be countersigning? could you be countersigning? could they be countersigning?
Perfect	V-ing perfect
could I have countersigned? could you have countersigned? could she have countersigned? could we have countersigned? could you have countersigned? could they have countersigned?	could I have been countersigning? could you have been countersigning? could she have been countersigning? could we have been countersigning? could you have been countersigning? could they have been countersigning?

Interro-negative form

Simple form	V-ing form
couldn't I countersign? couldn't you countersign? couldn't she countersign? couldn't we countersign? couldn't you countersign? couldn't they countersign?	couldn't I be countersigning? couldn't you be countersigning? couldn't she be countersigning? couldn't we be countersigning? couldn't you be countersigning? couldn't they be countersigning?
Perfect	V-ing perfect
couldn't I have countersigned? couldn't you have countersigned? couldn't she have countersigned? couldn't we have countersigned? couldn't you have countersigned? couldn't they have countersigned?	couldn't I have been countersigning? couldn't you have been countersigning? couldn't she have been countersigning? couldn't we have been countersigning? couldn't you have been countersigning? couldn't they have been countersigning?