English verb conjugation
MUST EXTEND

Regular verb: extend - extended - extended

Affirmation

Simple form	V-ing form
I must extend you must extend she must extend we must extend you must extend they must extend	I must be extending you must be extending she must be extending we must be extending you must be extending they must be extending
Perfect	V-ing perfect
I must have extended you must have extended she must have extended we must have extended you must have extended they must have extended	I must have been extending you must have been extending she must have been extending we must have been extending you must have been extending they must have been extending

Negation

Simple form	V-ing form
I mustn't extend you mustn't extend she mustn't extend we mustn't extend you mustn't extend they mustn't extend	I mustn't be extending you mustn't be extending she mustn't be extending we mustn't be extending you mustn't be extending they mustn't be extending
Perfect	V-ing perfect
I mustn't have extended you mustn't have extended she mustn't have extended we mustn't have extended you mustn't have extended they mustn't have extended	I mustn't have been extending you mustn't have been extending she mustn't have been extending we mustn't have been extending you mustn't have been extending they mustn't have been extending

Interrogative form

Simple form	V-ing form
must I extend? must you extend? must she extend? must we extend? must you extend? must they extend?	must I be extending? must you be extending? must she be extending? must we be extending? must you be extending? must they be extending?
Perfect	V-ing perfect
must I have extended? must you have extended? must she have extended? must we have extended? must you have extended? must they have extended?	must I have been extending? must you have been extending? must she have been extending? must we have been extending? must you have been extending? must they have been extending?

Interro-negative form

Simple form	V-ing form
mustn't I extend? mustn't you extend? mustn't she extend? mustn't we extend? mustn't you extend? mustn't they extend?	mustn't I be extending? mustn't you be extending? mustn't she be extending? mustn't we be extending? mustn't you be extending? mustn't they be extending?
Perfect	V-ing perfect
mustn't I have extended? mustn't you have extended? mustn't she have extended? mustn't we have extended? mustn't you have extended? mustn't they have extended?	mustn't I have been extending? mustn't you have been extending? mustn't she have been extending? mustn't we have been extending? mustn't you have been extending? mustn't they have been extending?