English verb conjugation
MUST RETROFIT

Irregular verb: retrofit - retrofit - retrofit

Affirmation

Simple form	V-ing form
I must retrofit you must retrofit he must retrofit we must retrofit you must retrofit they must retrofit	I must be retrofiting you must be retrofiting he must be retrofiting we must be retrofiting you must be retrofiting they must be retrofiting
Perfect	V-ing perfect
I must have retrofit you must have retrofit he must have retrofit we must have retrofit you must have retrofit they must have retrofit	I must have been retrofiting you must have been retrofiting he must have been retrofiting we must have been retrofiting you must have been retrofiting they must have been retrofiting

Negation

Simple form	V-ing form
I mustn't retrofit you mustn't retrofit he mustn't retrofit we mustn't retrofit you mustn't retrofit they mustn't retrofit	I mustn't be retrofiting you mustn't be retrofiting he mustn't be retrofiting we mustn't be retrofiting you mustn't be retrofiting they mustn't be retrofiting
Perfect	V-ing perfect
I mustn't have retrofit you mustn't have retrofit he mustn't have retrofit we mustn't have retrofit you mustn't have retrofit they mustn't have retrofit	I mustn't have been retrofiting you mustn't have been retrofiting he mustn't have been retrofiting we mustn't have been retrofiting you mustn't have been retrofiting they mustn't have been retrofiting

Interrogative form

Simple form	V-ing form
must I retrofit? must you retrofit? must he retrofit? must we retrofit? must you retrofit? must they retrofit?	must I be retrofiting? must you be retrofiting? must he be retrofiting? must we be retrofiting? must you be retrofiting? must they be retrofiting?
Perfect	V-ing perfect
must I have retrofit? must you have retrofit? must he have retrofit? must we have retrofit? must you have retrofit? must they have retrofit?	must I have been retrofiting? must you have been retrofiting? must he have been retrofiting? must we have been retrofiting? must you have been retrofiting? must they have been retrofiting?

Interro-negative form

Simple form	V-ing form
mustn't I retrofit? mustn't you retrofit? mustn't he retrofit? mustn't we retrofit? mustn't you retrofit? mustn't they retrofit?	mustn't I be retrofiting? mustn't you be retrofiting? mustn't he be retrofiting? mustn't we be retrofiting? mustn't you be retrofiting? mustn't they be retrofiting?
Perfect	V-ing perfect
mustn't I have retrofit? mustn't you have retrofit? mustn't he have retrofit? mustn't we have retrofit? mustn't you have retrofit? mustn't they have retrofit?	mustn't I have been retrofiting? mustn't you have been retrofiting? mustn't he have been retrofiting? mustn't we have been retrofiting? mustn't you have been retrofiting? mustn't they have been retrofiting?