English verb conjugation
MUST COMBINE

Regular verb: combine - combined - combined

Affirmation

Simple form	V-ing form
I must combine you must combine he must combine we must combine you must combine they must combine	I must be combining you must be combining he must be combining we must be combining you must be combining they must be combining
Perfect	V-ing perfect
I must have combined you must have combined he must have combined we must have combined you must have combined they must have combined	I must have been combining you must have been combining he must have been combining we must have been combining you must have been combining they must have been combining

Negation

Simple form	V-ing form
I mustn't combine you mustn't combine he mustn't combine we mustn't combine you mustn't combine they mustn't combine	I mustn't be combining you mustn't be combining he mustn't be combining we mustn't be combining you mustn't be combining they mustn't be combining
Perfect	V-ing perfect
I mustn't have combined you mustn't have combined he mustn't have combined we mustn't have combined you mustn't have combined they mustn't have combined	I mustn't have been combining you mustn't have been combining he mustn't have been combining we mustn't have been combining you mustn't have been combining they mustn't have been combining

Interrogative form

Simple form	V-ing form
must I combine? must you combine? must he combine? must we combine? must you combine? must they combine?	must I be combining? must you be combining? must he be combining? must we be combining? must you be combining? must they be combining?
Perfect	V-ing perfect
must I have combined? must you have combined? must he have combined? must we have combined? must you have combined? must they have combined?	must I have been combining? must you have been combining? must he have been combining? must we have been combining? must you have been combining? must they have been combining?

Interro-negative form

Simple form	V-ing form
mustn't I combine? mustn't you combine? mustn't he combine? mustn't we combine? mustn't you combine? mustn't they combine?	mustn't I be combining? mustn't you be combining? mustn't he be combining? mustn't we be combining? mustn't you be combining? mustn't they be combining?
Perfect	V-ing perfect
mustn't I have combined? mustn't you have combined? mustn't he have combined? mustn't we have combined? mustn't you have combined? mustn't they have combined?	mustn't I have been combining? mustn't you have been combining? mustn't he have been combining? mustn't we have been combining? mustn't you have been combining? mustn't they have been combining?