English verb conjugation
MUST LAG

Regular verb: lag - lagged - lagged

Affirmation

Simple form	V-ing form
I must lag you must lag he must lag we must lag you must lag they must lag	I must be lagging you must be lagging he must be lagging we must be lagging you must be lagging they must be lagging
Perfect	V-ing perfect
I must have lagged you must have lagged he must have lagged we must have lagged you must have lagged they must have lagged	I must have been lagging you must have been lagging he must have been lagging we must have been lagging you must have been lagging they must have been lagging

Negation

Simple form	V-ing form
I mustn't lag you mustn't lag he mustn't lag we mustn't lag you mustn't lag they mustn't lag	I mustn't be lagging you mustn't be lagging he mustn't be lagging we mustn't be lagging you mustn't be lagging they mustn't be lagging
Perfect	V-ing perfect
I mustn't have lagged you mustn't have lagged he mustn't have lagged we mustn't have lagged you mustn't have lagged they mustn't have lagged	I mustn't have been lagging you mustn't have been lagging he mustn't have been lagging we mustn't have been lagging you mustn't have been lagging they mustn't have been lagging

Interrogative form

Simple form	V-ing form
must I lag? must you lag? must he lag? must we lag? must you lag? must they lag?	must I be lagging? must you be lagging? must he be lagging? must we be lagging? must you be lagging? must they be lagging?
Perfect	V-ing perfect
must I have lagged? must you have lagged? must he have lagged? must we have lagged? must you have lagged? must they have lagged?	must I have been lagging? must you have been lagging? must he have been lagging? must we have been lagging? must you have been lagging? must they have been lagging?

Interro-negative form

Simple form	V-ing form
mustn't I lag? mustn't you lag? mustn't he lag? mustn't we lag? mustn't you lag? mustn't they lag?	mustn't I be lagging? mustn't you be lagging? mustn't he be lagging? mustn't we be lagging? mustn't you be lagging? mustn't they be lagging?
Perfect	V-ing perfect
mustn't I have lagged? mustn't you have lagged? mustn't he have lagged? mustn't we have lagged? mustn't you have lagged? mustn't they have lagged?	mustn't I have been lagging? mustn't you have been lagging? mustn't he have been lagging? mustn't we have been lagging? mustn't you have been lagging? mustn't they have been lagging?