must piece
Verbo regular: piece - pieced- pieced

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must piece
you must piece
he must piece
we must piece
you must piece
they must piece 	I must be piecing
you must be piecing
he must be piecing
we must be piecing
you must be piecing
they must be piecing	I must have pieced
you must have pieced
he must have pieced
we must have pieced
you must have pieced
they must have pieced	I must have been piecing
you must have been piecing
he must have been piecing
we must have been piecing
you must have been piecing
they must have been piecing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't piece
you mustn't piece
he mustn't piece
we mustn't piece
you mustn't piece
they mustn't piece 	I mustn't be piecing
you mustn't be piecing
he mustn't be piecing
we mustn't be piecing
you mustn't be piecing
they mustn't be piecing	I mustn't have pieced
you mustn't have pieced
he mustn't have pieced
we mustn't have pieced
you mustn't have pieced
they mustn't have pieced	I mustn't have been piecing
you mustn't have been piecing
he mustn't have been piecing
we mustn't have been piecing
you mustn't have been piecing
they mustn't have been piecing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I piece?
must you piece?
must he piece?
must we piece?
must you piece?
must they piece? 	must I be piecing?
must you be piecing?
must he be piecing?
must we be piecing?
must you be piecing?
must they be piecing? 	must I have pieced?
must you have pieced?
must he have pieced?
must we have pieced?
must you have pieced?
must they have pieced? 	must I have been piecing?
must you have been piecing?
must he have been piecing?
must we have been piecing?
must you have been piecing?
must they have been piecing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I piece?
mustn't you piece?
mustn't he piece?
mustn't we piece?
mustn't you piece?
mustn't they piece? 	mustn't I be piecing?
mustn't you be piecing?
mustn't he be piecing?
mustn't we be piecing?
mustn't you be piecing?
mustn't they be piecing? 	mustn't I have pieced?
mustn't you have pieced?
mustn't he have pieced?
mustn't we have pieced?
mustn't you have pieced?
mustn't they have pieced? 	mustn't I have been piecing?
mustn't you have been piecing?
mustn't he have been piecing?
mustn't we have been piecing?
mustn't you have been piecing?
mustn't they have been piecing?