English verb conjugation
MUST CONCENTRATE

Regular verb: concentrate - concentrated - concentrated

Affirmation

Simple form	V-ing form
I must concentrate you must concentrate he must concentrate we must concentrate you must concentrate they must concentrate	I must be concentrating you must be concentrating he must be concentrating we must be concentrating you must be concentrating they must be concentrating
Perfect	V-ing perfect
I must have concentrated you must have concentrated he must have concentrated we must have concentrated you must have concentrated they must have concentrated	I must have been concentrating you must have been concentrating he must have been concentrating we must have been concentrating you must have been concentrating they must have been concentrating

Negation

Simple form	V-ing form
I mustn't concentrate you mustn't concentrate he mustn't concentrate we mustn't concentrate you mustn't concentrate they mustn't concentrate	I mustn't be concentrating you mustn't be concentrating he mustn't be concentrating we mustn't be concentrating you mustn't be concentrating they mustn't be concentrating
Perfect	V-ing perfect
I mustn't have concentrated you mustn't have concentrated he mustn't have concentrated we mustn't have concentrated you mustn't have concentrated they mustn't have concentrated	I mustn't have been concentrating you mustn't have been concentrating he mustn't have been concentrating we mustn't have been concentrating you mustn't have been concentrating they mustn't have been concentrating

Interrogative form

Simple form	V-ing form
must I concentrate? must you concentrate? must he concentrate? must we concentrate? must you concentrate? must they concentrate?	must I be concentrating? must you be concentrating? must he be concentrating? must we be concentrating? must you be concentrating? must they be concentrating?
Perfect	V-ing perfect
must I have concentrated? must you have concentrated? must he have concentrated? must we have concentrated? must you have concentrated? must they have concentrated?	must I have been concentrating? must you have been concentrating? must he have been concentrating? must we have been concentrating? must you have been concentrating? must they have been concentrating?

Interro-negative form

Simple form	V-ing form
mustn't I concentrate? mustn't you concentrate? mustn't he concentrate? mustn't we concentrate? mustn't you concentrate? mustn't they concentrate?	mustn't I be concentrating? mustn't you be concentrating? mustn't he be concentrating? mustn't we be concentrating? mustn't you be concentrating? mustn't they be concentrating?
Perfect	V-ing perfect
mustn't I have concentrated? mustn't you have concentrated? mustn't he have concentrated? mustn't we have concentrated? mustn't you have concentrated? mustn't they have concentrated?	mustn't I have been concentrating? mustn't you have been concentrating? mustn't he have been concentrating? mustn't we have been concentrating? mustn't you have been concentrating? mustn't they have been concentrating?