English verb conjugation
MUST BUCK

Regular verb: buck - bucked - bucked

Affirmation

Simple form	V-ing form
I must buck you must buck she must buck we must buck you must buck they must buck	I must be bucking you must be bucking she must be bucking we must be bucking you must be bucking they must be bucking
Perfect	V-ing perfect
I must have bucked you must have bucked she must have bucked we must have bucked you must have bucked they must have bucked	I must have been bucking you must have been bucking she must have been bucking we must have been bucking you must have been bucking they must have been bucking

Negation

Simple form	V-ing form
I mustn't buck you mustn't buck she mustn't buck we mustn't buck you mustn't buck they mustn't buck	I mustn't be bucking you mustn't be bucking she mustn't be bucking we mustn't be bucking you mustn't be bucking they mustn't be bucking
Perfect	V-ing perfect
I mustn't have bucked you mustn't have bucked she mustn't have bucked we mustn't have bucked you mustn't have bucked they mustn't have bucked	I mustn't have been bucking you mustn't have been bucking she mustn't have been bucking we mustn't have been bucking you mustn't have been bucking they mustn't have been bucking

Interrogative form

Simple form	V-ing form
must I buck? must you buck? must she buck? must we buck? must you buck? must they buck?	must I be bucking? must you be bucking? must she be bucking? must we be bucking? must you be bucking? must they be bucking?
Perfect	V-ing perfect
must I have bucked? must you have bucked? must she have bucked? must we have bucked? must you have bucked? must they have bucked?	must I have been bucking? must you have been bucking? must she have been bucking? must we have been bucking? must you have been bucking? must they have been bucking?

Interro-negative form

Simple form	V-ing form
mustn't I buck? mustn't you buck? mustn't she buck? mustn't we buck? mustn't you buck? mustn't they buck?	mustn't I be bucking? mustn't you be bucking? mustn't she be bucking? mustn't we be bucking? mustn't you be bucking? mustn't they be bucking?
Perfect	V-ing perfect
mustn't I have bucked? mustn't you have bucked? mustn't she have bucked? mustn't we have bucked? mustn't you have bucked? mustn't they have bucked?	mustn't I have been bucking? mustn't you have been bucking? mustn't she have been bucking? mustn't we have been bucking? mustn't you have been bucking? mustn't they have been bucking?