English verb conjugation
SHOULD PREHEAT

Regular verb: preheat - preheated - preheated

Affirmation

Simple form	V-ing form
I'd preheat you'd preheat he'd preheat we'd preheat you'd preheat they'd preheat	I'd be preheating you'd be preheating he'd be preheating we'd be preheating you'd be preheating they'd be preheating
Perfect	V-ing perfect
I should've preheated you should've preheated he should've preheated we should've preheated you should've preheated they should've preheated	I should've been preheating you should've been preheating he should've been preheating we should've been preheating you should've been preheating they should've been preheating

Negation

Simple form	V-ing form
I shouldn't preheat you shouldn't preheat he shouldn't preheat we shouldn't preheat you shouldn't preheat they shouldn't preheat	I shouldn't be preheating you shouldn't be preheating he shouldn't be preheating we shouldn't be preheating you shouldn't be preheating they shouldn't be preheating
Perfect	V-ing perfect
I shouldn't have preheated you shouldn't have preheated he shouldn't have preheated we shouldn't have preheated you shouldn't have preheated they shouldn't have preheated	I shouldn't have been preheating you shouldn't have been preheating he shouldn't have been preheating we shouldn't have been preheating you shouldn't have been preheating they shouldn't have been preheating

Interrogative form

Simple form	V-ing form
should I preheat? should you preheat? should he preheat? should we preheat? should you preheat? should they preheat?	should I be preheating? should you be preheating? should he be preheating? should we be preheating? should you be preheating? should they be preheating?
Perfect	V-ing perfect
should I have preheated? should you have preheated? should he have preheated? should we have preheated? should you have preheated? should they have preheated?	should I have been preheating? should you have been preheating? should he have been preheating? should we have been preheating? should you have been preheating? should they have been preheating?

Interro-negative form

Simple form	V-ing form
shouldn't I preheat? shouldn't you preheat? shouldn't he preheat? shouldn't we preheat? shouldn't you preheat? shouldn't they preheat?	shouldn't I be preheating? shouldn't you be preheating? shouldn't he be preheating? shouldn't we be preheating? shouldn't you be preheating? shouldn't they be preheating?
Perfect	V-ing perfect
shouldn't I have preheated? shouldn't you have preheated? shouldn't he have preheated? shouldn't we have preheated? shouldn't you have preheated? shouldn't they have preheated?	shouldn't I have been preheating? shouldn't you have been preheating? shouldn't he have been preheating? shouldn't we have been preheating? shouldn't you have been preheating? shouldn't they have been preheating?