English verb conjugation
SHOULD SUSTAIN

Regular verb: sustain - sustained - sustained

Affirmation

Simple form	V-ing form
I'd sustain you'd sustain he'd sustain we'd sustain you'd sustain they'd sustain	I'd be sustaining you'd be sustaining he'd be sustaining we'd be sustaining you'd be sustaining they'd be sustaining
Perfect	V-ing perfect
I should've sustained you should've sustained he should've sustained we should've sustained you should've sustained they should've sustained	I should've been sustaining you should've been sustaining he should've been sustaining we should've been sustaining you should've been sustaining they should've been sustaining

Negation

Simple form	V-ing form
I shouldn't sustain you shouldn't sustain he shouldn't sustain we shouldn't sustain you shouldn't sustain they shouldn't sustain	I shouldn't be sustaining you shouldn't be sustaining he shouldn't be sustaining we shouldn't be sustaining you shouldn't be sustaining they shouldn't be sustaining
Perfect	V-ing perfect
I shouldn't have sustained you shouldn't have sustained he shouldn't have sustained we shouldn't have sustained you shouldn't have sustained they shouldn't have sustained	I shouldn't have been sustaining you shouldn't have been sustaining he shouldn't have been sustaining we shouldn't have been sustaining you shouldn't have been sustaining they shouldn't have been sustaining

Interrogative form

Simple form	V-ing form
should I sustain? should you sustain? should he sustain? should we sustain? should you sustain? should they sustain?	should I be sustaining? should you be sustaining? should he be sustaining? should we be sustaining? should you be sustaining? should they be sustaining?
Perfect	V-ing perfect
should I have sustained? should you have sustained? should he have sustained? should we have sustained? should you have sustained? should they have sustained?	should I have been sustaining? should you have been sustaining? should he have been sustaining? should we have been sustaining? should you have been sustaining? should they have been sustaining?

Interro-negative form

Simple form	V-ing form
shouldn't I sustain? shouldn't you sustain? shouldn't he sustain? shouldn't we sustain? shouldn't you sustain? shouldn't they sustain?	shouldn't I be sustaining? shouldn't you be sustaining? shouldn't he be sustaining? shouldn't we be sustaining? shouldn't you be sustaining? shouldn't they be sustaining?
Perfect	V-ing perfect
shouldn't I have sustained? shouldn't you have sustained? shouldn't he have sustained? shouldn't we have sustained? shouldn't you have sustained? shouldn't they have sustained?	shouldn't I have been sustaining? shouldn't you have been sustaining? shouldn't he have been sustaining? shouldn't we have been sustaining? shouldn't you have been sustaining? shouldn't they have been sustaining?