English verb conjugation
SHOULD WARN

Regular verb: warn - warned - warned

Affirmation

Simple form	V-ing form
I'd warn you'd warn he'd warn we'd warn you'd warn they'd warn	I'd be warning you'd be warning he'd be warning we'd be warning you'd be warning they'd be warning
Perfect	V-ing perfect
I should've warned you should've warned he should've warned we should've warned you should've warned they should've warned	I should've been warning you should've been warning he should've been warning we should've been warning you should've been warning they should've been warning

Negation

Simple form	V-ing form
I shouldn't warn you shouldn't warn he shouldn't warn we shouldn't warn you shouldn't warn they shouldn't warn	I shouldn't be warning you shouldn't be warning he shouldn't be warning we shouldn't be warning you shouldn't be warning they shouldn't be warning
Perfect	V-ing perfect
I shouldn't have warned you shouldn't have warned he shouldn't have warned we shouldn't have warned you shouldn't have warned they shouldn't have warned	I shouldn't have been warning you shouldn't have been warning he shouldn't have been warning we shouldn't have been warning you shouldn't have been warning they shouldn't have been warning

Interrogative form

Simple form	V-ing form
should I warn? should you warn? should he warn? should we warn? should you warn? should they warn?	should I be warning? should you be warning? should he be warning? should we be warning? should you be warning? should they be warning?
Perfect	V-ing perfect
should I have warned? should you have warned? should he have warned? should we have warned? should you have warned? should they have warned?	should I have been warning? should you have been warning? should he have been warning? should we have been warning? should you have been warning? should they have been warning?

Interro-negative form

Simple form	V-ing form
shouldn't I warn? shouldn't you warn? shouldn't he warn? shouldn't we warn? shouldn't you warn? shouldn't they warn?	shouldn't I be warning? shouldn't you be warning? shouldn't he be warning? shouldn't we be warning? shouldn't you be warning? shouldn't they be warning?
Perfect	V-ing perfect
shouldn't I have warned? shouldn't you have warned? shouldn't he have warned? shouldn't we have warned? shouldn't you have warned? shouldn't they have warned?	shouldn't I have been warning? shouldn't you have been warning? shouldn't he have been warning? shouldn't we have been warning? shouldn't you have been warning? shouldn't they have been warning?