should preheat
Regular verb: preheat - preheated- preheated

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

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should not preheat
you should not preheat
he should not preheat
we should not preheat
you should not preheat
they should not preheat 	I should not be preheating
you should not be preheating
he should not be preheating
we should not be preheating
you should not be preheating
they should not be preheating	I should not have preheated
you should not have preheated
he should not have preheated
we should not have preheated
you should not have preheated
they should not have preheated	I should not have been preheating
you should not have been preheating
he should not have been preheating
we should not have been preheating
you should not have been preheating
they should not have been preheating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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? 	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 	Perfect 	V-ing perfect 	
should I not preheat?
should you not preheat?
should he not preheat?
should we not preheat?
should you not preheat?
should they not preheat? 	should I not be preheating?
should you not be preheating?
should he not be preheating?
should we not be preheating?
should you not be preheating?
should they not be preheating? 	should I not have preheated?
should you not have preheated?
should he not have preheated?
should we not have preheated?
should you not have preheated?
should they not have preheated? 	should I not have been preheating?
should you not have been preheating?
should he not have been preheating?
should we not have been preheating?
should you not have been preheating?
should they not have been preheating?