English verb conjugation
MUST SPEC

Regular verb: spec - speced - speced

Affirmation

Simple form	V-ing form
I must spec you must spec he must spec we must spec you must spec they must spec	I must be specing you must be specing he must be specing we must be specing you must be specing they must be specing
Perfect	V-ing perfect
I must have speced you must have speced he must have speced we must have speced you must have speced they must have speced	I must have been specing you must have been specing he must have been specing we must have been specing you must have been specing they must have been specing

Negation

Simple form	V-ing form
I mustn't spec you mustn't spec he mustn't spec we mustn't spec you mustn't spec they mustn't spec	I mustn't be specing you mustn't be specing he mustn't be specing we mustn't be specing you mustn't be specing they mustn't be specing
Perfect	V-ing perfect
I mustn't have speced you mustn't have speced he mustn't have speced we mustn't have speced you mustn't have speced they mustn't have speced	I mustn't have been specing you mustn't have been specing he mustn't have been specing we mustn't have been specing you mustn't have been specing they mustn't have been specing

Interrogative form

Simple form	V-ing form
must I spec? must you spec? must he spec? must we spec? must you spec? must they spec?	must I be specing? must you be specing? must he be specing? must we be specing? must you be specing? must they be specing?
Perfect	V-ing perfect
must I have speced? must you have speced? must he have speced? must we have speced? must you have speced? must they have speced?	must I have been specing? must you have been specing? must he have been specing? must we have been specing? must you have been specing? must they have been specing?

Interro-negative form

Simple form	V-ing form
mustn't I spec? mustn't you spec? mustn't he spec? mustn't we spec? mustn't you spec? mustn't they spec?	mustn't I be specing? mustn't you be specing? mustn't he be specing? mustn't we be specing? mustn't you be specing? mustn't they be specing?
Perfect	V-ing perfect
mustn't I have speced? mustn't you have speced? mustn't he have speced? mustn't we have speced? mustn't you have speced? mustn't they have speced?	mustn't I have been specing? mustn't you have been specing? mustn't he have been specing? mustn't we have been specing? mustn't you have been specing? mustn't they have been specing?