must buck
Regular verb: buck - bucked- bucked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must buck
you must buck
he must buck
we must buck
you must buck
they must buck 	I must be bucking
you must be bucking
he must be bucking
we must be bucking
you must be bucking
they must be bucking	I must have bucked
you must have bucked
he 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
he 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 	Perfect 	V-ing perfect 	
I must not buck
you must not buck
he must not buck
we must not buck
you must not buck
they must not buck 	I must not be bucking
you must not be bucking
he must not be bucking
we must not be bucking
you must not be bucking
they must not be bucking	I must not have bucked
you must not have bucked
he must not have bucked
we must not have bucked
you must not have bucked
they must not have bucked	I must not have been bucking
you must not have been bucking
he must not have been bucking
we must not have been bucking
you must not have been bucking
they must not have been bucking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I buck?
must you buck?
must he buck?
must we buck?
must you buck?
must they buck? 	must I be bucking?
must you be bucking?
must he be bucking?
must we be bucking?
must you be bucking?
must they be bucking? 	must I have bucked?
must you have bucked?
must he 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 he 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 	Perfect 	V-ing perfect 	
must I not buck?
must you not buck?
must he not buck?
must we not buck?
must you not buck?
must they not buck? 	must I not be bucking?
must you not be bucking?
must he not be bucking?
must we not be bucking?
must you not be bucking?
must they not be bucking? 	must I not have bucked?
must you not have bucked?
must he not have bucked?
must we not have bucked?
must you not have bucked?
must they not have bucked? 	must I not have been bucking?
must you not have been bucking?
must he not have been bucking?
must we not have been bucking?
must you not have been bucking?
must they not have been bucking?