must blunder
Regular verb: blunder - blundered- blundered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must blunder
you must blunder
she must blunder
we must blunder
you must blunder
they must blunder 	I must be blundering
you must be blundering
she must be blundering
we must be blundering
you must be blundering
they must be blundering	I must have blundered
you must have blundered
she must have blundered
we must have blundered
you must have blundered
they must have blundered	I must have been blundering
you must have been blundering
she must have been blundering
we must have been blundering
you must have been blundering
they must have been blundering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't blunder
you mustn't blunder
she mustn't blunder
we mustn't blunder
you mustn't blunder
they mustn't blunder 	I mustn't be blundering
you mustn't be blundering
she mustn't be blundering
we mustn't be blundering
you mustn't be blundering
they mustn't be blundering	I mustn't have blundered
you mustn't have blundered
she mustn't have blundered
we mustn't have blundered
you mustn't have blundered
they mustn't have blundered	I mustn't have been blundering
you mustn't have been blundering
she mustn't have been blundering
we mustn't have been blundering
you mustn't have been blundering
they mustn't have been blundering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I blunder?
must you blunder?
must she blunder?
must we blunder?
must you blunder?
must they blunder? 	must I be blundering?
must you be blundering?
must she be blundering?
must we be blundering?
must you be blundering?
must they be blundering? 	must I have blundered?
must you have blundered?
must she have blundered?
must we have blundered?
must you have blundered?
must they have blundered? 	must I have been blundering?
must you have been blundering?
must she have been blundering?
must we have been blundering?
must you have been blundering?
must they have been blundering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I blunder?
mustn't you blunder?
mustn't she blunder?
mustn't we blunder?
mustn't you blunder?
mustn't they blunder? 	mustn't I be blundering?
mustn't you be blundering?
mustn't she be blundering?
mustn't we be blundering?
mustn't you be blundering?
mustn't they be blundering? 	mustn't I have blundered?
mustn't you have blundered?
mustn't she have blundered?
mustn't we have blundered?
mustn't you have blundered?
mustn't they have blundered? 	mustn't I have been blundering?
mustn't you have been blundering?
mustn't she have been blundering?
mustn't we have been blundering?
mustn't you have been blundering?
mustn't they have been blundering?