English verb conjugation
MUST SURF

Regular verb: surf - surfed - surfed

Affirmation

Simple form	V-ing form
I must surf you must surf she must surf we must surf you must surf they must surf	I must be surfing you must be surfing she must be surfing we must be surfing you must be surfing they must be surfing
Perfect	V-ing perfect
I must have surfed you must have surfed she must have surfed we must have surfed you must have surfed they must have surfed	I must have been surfing you must have been surfing she must have been surfing we must have been surfing you must have been surfing they must have been surfing

Negation

Simple form	V-ing form
I mustn't surf you mustn't surf she mustn't surf we mustn't surf you mustn't surf they mustn't surf	I mustn't be surfing you mustn't be surfing she mustn't be surfing we mustn't be surfing you mustn't be surfing they mustn't be surfing
Perfect	V-ing perfect
I mustn't have surfed you mustn't have surfed she mustn't have surfed we mustn't have surfed you mustn't have surfed they mustn't have surfed	I mustn't have been surfing you mustn't have been surfing she mustn't have been surfing we mustn't have been surfing you mustn't have been surfing they mustn't have been surfing

Interrogative form

Simple form	V-ing form
must I surf? must you surf? must she surf? must we surf? must you surf? must they surf?	must I be surfing? must you be surfing? must she be surfing? must we be surfing? must you be surfing? must they be surfing?
Perfect	V-ing perfect
must I have surfed? must you have surfed? must she have surfed? must we have surfed? must you have surfed? must they have surfed?	must I have been surfing? must you have been surfing? must she have been surfing? must we have been surfing? must you have been surfing? must they have been surfing?

Interro-negative form

Simple form	V-ing form
mustn't I surf? mustn't you surf? mustn't she surf? mustn't we surf? mustn't you surf? mustn't they surf?	mustn't I be surfing? mustn't you be surfing? mustn't she be surfing? mustn't we be surfing? mustn't you be surfing? mustn't they be surfing?
Perfect	V-ing perfect
mustn't I have surfed? mustn't you have surfed? mustn't she have surfed? mustn't we have surfed? mustn't you have surfed? mustn't they have surfed?	mustn't I have been surfing? mustn't you have been surfing? mustn't she have been surfing? mustn't we have been surfing? mustn't you have been surfing? mustn't they have been surfing?