English verb conjugation
MUST CREAK

Regular verb: creak - creaked - creaked

Affirmation

Simple form	V-ing form
I must creak you must creak he must creak we must creak you must creak they must creak	I must be creaking you must be creaking he must be creaking we must be creaking you must be creaking they must be creaking
Perfect	V-ing perfect
I must have creaked you must have creaked he must have creaked we must have creaked you must have creaked they must have creaked	I must have been creaking you must have been creaking he must have been creaking we must have been creaking you must have been creaking they must have been creaking

Negation

Simple form	V-ing form
I mustn't creak you mustn't creak he mustn't creak we mustn't creak you mustn't creak they mustn't creak	I mustn't be creaking you mustn't be creaking he mustn't be creaking we mustn't be creaking you mustn't be creaking they mustn't be creaking
Perfect	V-ing perfect
I mustn't have creaked you mustn't have creaked he mustn't have creaked we mustn't have creaked you mustn't have creaked they mustn't have creaked	I mustn't have been creaking you mustn't have been creaking he mustn't have been creaking we mustn't have been creaking you mustn't have been creaking they mustn't have been creaking

Interrogative form

Simple form	V-ing form
must I creak? must you creak? must he creak? must we creak? must you creak? must they creak?	must I be creaking? must you be creaking? must he be creaking? must we be creaking? must you be creaking? must they be creaking?
Perfect	V-ing perfect
must I have creaked? must you have creaked? must he have creaked? must we have creaked? must you have creaked? must they have creaked?	must I have been creaking? must you have been creaking? must he have been creaking? must we have been creaking? must you have been creaking? must they have been creaking?

Interro-negative form

Simple form	V-ing form
mustn't I creak? mustn't you creak? mustn't he creak? mustn't we creak? mustn't you creak? mustn't they creak?	mustn't I be creaking? mustn't you be creaking? mustn't he be creaking? mustn't we be creaking? mustn't you be creaking? mustn't they be creaking?
Perfect	V-ing perfect
mustn't I have creaked? mustn't you have creaked? mustn't he have creaked? mustn't we have creaked? mustn't you have creaked? mustn't they have creaked?	mustn't I have been creaking? mustn't you have been creaking? mustn't he have been creaking? mustn't we have been creaking? mustn't you have been creaking? mustn't they have been creaking?