English verb conjugation
SHOULD SUM

Regular verb: sum - summed - summed

Affirmation

Simple form	V-ing form
I'd sum you'd sum he'd sum we'd sum you'd sum they'd sum	I'd be summing you'd be summing he'd be summing we'd be summing you'd be summing they'd be summing
Perfect	V-ing perfect
I should've summed you should've summed he should've summed we should've summed you should've summed they should've summed	I should've been summing you should've been summing he should've been summing we should've been summing you should've been summing they should've been summing

Negation

Simple form	V-ing form
I shouldn't sum you shouldn't sum he shouldn't sum we shouldn't sum you shouldn't sum they shouldn't sum	I shouldn't be summing you shouldn't be summing he shouldn't be summing we shouldn't be summing you shouldn't be summing they shouldn't be summing
Perfect	V-ing perfect
I shouldn't have summed you shouldn't have summed he shouldn't have summed we shouldn't have summed you shouldn't have summed they shouldn't have summed	I shouldn't have been summing you shouldn't have been summing he shouldn't have been summing we shouldn't have been summing you shouldn't have been summing they shouldn't have been summing

Interrogative form

Simple form	V-ing form
should I sum? should you sum? should he sum? should we sum? should you sum? should they sum?	should I be summing? should you be summing? should he be summing? should we be summing? should you be summing? should they be summing?
Perfect	V-ing perfect
should I have summed? should you have summed? should he have summed? should we have summed? should you have summed? should they have summed?	should I have been summing? should you have been summing? should he have been summing? should we have been summing? should you have been summing? should they have been summing?

Interro-negative form

Simple form	V-ing form
shouldn't I sum? shouldn't you sum? shouldn't he sum? shouldn't we sum? shouldn't you sum? shouldn't they sum?	shouldn't I be summing? shouldn't you be summing? shouldn't he be summing? shouldn't we be summing? shouldn't you be summing? shouldn't they be summing?
Perfect	V-ing perfect
shouldn't I have summed? shouldn't you have summed? shouldn't he have summed? shouldn't we have summed? shouldn't you have summed? shouldn't they have summed?	shouldn't I have been summing? shouldn't you have been summing? shouldn't he have been summing? shouldn't we have been summing? shouldn't you have been summing? shouldn't they have been summing?