English verb conjugation
SHOULD IMPUGN

Regular verb: impugn - impugned - impugned

Affirmation

Simple form	V-ing form
I'd impugn you'd impugn he'd impugn we'd impugn you'd impugn they'd impugn	I'd be impugning you'd be impugning he'd be impugning we'd be impugning you'd be impugning they'd be impugning
Perfect	V-ing perfect
I should've impugned you should've impugned he should've impugned we should've impugned you should've impugned they should've impugned	I should've been impugning you should've been impugning he should've been impugning we should've been impugning you should've been impugning they should've been impugning

Negation

Simple form	V-ing form
I shouldn't impugn you shouldn't impugn he shouldn't impugn we shouldn't impugn you shouldn't impugn they shouldn't impugn	I shouldn't be impugning you shouldn't be impugning he shouldn't be impugning we shouldn't be impugning you shouldn't be impugning they shouldn't be impugning
Perfect	V-ing perfect
I shouldn't have impugned you shouldn't have impugned he shouldn't have impugned we shouldn't have impugned you shouldn't have impugned they shouldn't have impugned	I shouldn't have been impugning you shouldn't have been impugning he shouldn't have been impugning we shouldn't have been impugning you shouldn't have been impugning they shouldn't have been impugning

Interrogative form

Simple form	V-ing form
should I impugn? should you impugn? should he impugn? should we impugn? should you impugn? should they impugn?	should I be impugning? should you be impugning? should he be impugning? should we be impugning? should you be impugning? should they be impugning?
Perfect	V-ing perfect
should I have impugned? should you have impugned? should he have impugned? should we have impugned? should you have impugned? should they have impugned?	should I have been impugning? should you have been impugning? should he have been impugning? should we have been impugning? should you have been impugning? should they have been impugning?

Interro-negative form

Simple form	V-ing form
shouldn't I impugn? shouldn't you impugn? shouldn't he impugn? shouldn't we impugn? shouldn't you impugn? shouldn't they impugn?	shouldn't I be impugning? shouldn't you be impugning? shouldn't he be impugning? shouldn't we be impugning? shouldn't you be impugning? shouldn't they be impugning?
Perfect	V-ing perfect
shouldn't I have impugned? shouldn't you have impugned? shouldn't he have impugned? shouldn't we have impugned? shouldn't you have impugned? shouldn't they have impugned?	shouldn't I have been impugning? shouldn't you have been impugning? shouldn't he have been impugning? shouldn't we have been impugning? shouldn't you have been impugning? shouldn't they have been impugning?