English verb conjugation
MUST COMBUST

Regular verb: combust - combusted - combusted

Affirmation

Simple form	V-ing form
I must combust you must combust he must combust we must combust you must combust they must combust	I must be combusting you must be combusting he must be combusting we must be combusting you must be combusting they must be combusting
Perfect	V-ing perfect
I must have combusted you must have combusted he must have combusted we must have combusted you must have combusted they must have combusted	I must have been combusting you must have been combusting he must have been combusting we must have been combusting you must have been combusting they must have been combusting

Negation

Simple form	V-ing form
I mustn't combust you mustn't combust he mustn't combust we mustn't combust you mustn't combust they mustn't combust	I mustn't be combusting you mustn't be combusting he mustn't be combusting we mustn't be combusting you mustn't be combusting they mustn't be combusting
Perfect	V-ing perfect
I mustn't have combusted you mustn't have combusted he mustn't have combusted we mustn't have combusted you mustn't have combusted they mustn't have combusted	I mustn't have been combusting you mustn't have been combusting he mustn't have been combusting we mustn't have been combusting you mustn't have been combusting they mustn't have been combusting

Interrogative form

Simple form	V-ing form
must I combust? must you combust? must he combust? must we combust? must you combust? must they combust?	must I be combusting? must you be combusting? must he be combusting? must we be combusting? must you be combusting? must they be combusting?
Perfect	V-ing perfect
must I have combusted? must you have combusted? must he have combusted? must we have combusted? must you have combusted? must they have combusted?	must I have been combusting? must you have been combusting? must he have been combusting? must we have been combusting? must you have been combusting? must they have been combusting?

Interro-negative form

Simple form	V-ing form
mustn't I combust? mustn't you combust? mustn't he combust? mustn't we combust? mustn't you combust? mustn't they combust?	mustn't I be combusting? mustn't you be combusting? mustn't he be combusting? mustn't we be combusting? mustn't you be combusting? mustn't they be combusting?
Perfect	V-ing perfect
mustn't I have combusted? mustn't you have combusted? mustn't he have combusted? mustn't we have combusted? mustn't you have combusted? mustn't they have combusted?	mustn't I have been combusting? mustn't you have been combusting? mustn't he have been combusting? mustn't we have been combusting? mustn't you have been combusting? mustn't they have been combusting?