English verb conjugation
MUST IMPROVE

Regular verb: improve - improved - improved

Affirmation

Simple form	V-ing form
I must improve you must improve he must improve we must improve you must improve they must improve	I must be improving you must be improving he must be improving we must be improving you must be improving they must be improving
Perfect	V-ing perfect
I must have improved you must have improved he must have improved we must have improved you must have improved they must have improved	I must have been improving you must have been improving he must have been improving we must have been improving you must have been improving they must have been improving

Negation

Simple form	V-ing form
I mustn't improve you mustn't improve he mustn't improve we mustn't improve you mustn't improve they mustn't improve	I mustn't be improving you mustn't be improving he mustn't be improving we mustn't be improving you mustn't be improving they mustn't be improving
Perfect	V-ing perfect
I mustn't have improved you mustn't have improved he mustn't have improved we mustn't have improved you mustn't have improved they mustn't have improved	I mustn't have been improving you mustn't have been improving he mustn't have been improving we mustn't have been improving you mustn't have been improving they mustn't have been improving

Interrogative form

Simple form	V-ing form
must I improve? must you improve? must he improve? must we improve? must you improve? must they improve?	must I be improving? must you be improving? must he be improving? must we be improving? must you be improving? must they be improving?
Perfect	V-ing perfect
must I have improved? must you have improved? must he have improved? must we have improved? must you have improved? must they have improved?	must I have been improving? must you have been improving? must he have been improving? must we have been improving? must you have been improving? must they have been improving?

Interro-negative form

Simple form	V-ing form
mustn't I improve? mustn't you improve? mustn't he improve? mustn't we improve? mustn't you improve? mustn't they improve?	mustn't I be improving? mustn't you be improving? mustn't he be improving? mustn't we be improving? mustn't you be improving? mustn't they be improving?
Perfect	V-ing perfect
mustn't I have improved? mustn't you have improved? mustn't he have improved? mustn't we have improved? mustn't you have improved? mustn't they have improved?	mustn't I have been improving? mustn't you have been improving? mustn't he have been improving? mustn't we have been improving? mustn't you have been improving? mustn't they have been improving?