English verb conjugation
MUST PREHEAT

Regular verb: preheat - preheated - preheated

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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