must tread
Verbo irregular: tread - trod- trod, trodden

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must tread
you must tread
he must tread
we must tread
you must tread
they must tread 	I must be treading
you must be treading
he must be treading
we must be treading
you must be treading
they must be treading	I must have trod, trodden
you must have trod, trodden
he must have trod, trodden
we must have trod, trodden
you must have trod, trodden
they must have trod, trodden	I must have been treading
you must have been treading
he must have been treading
we must have been treading
you must have been treading
they must have been treading	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't tread
you mustn't tread
he mustn't tread
we mustn't tread
you mustn't tread
they mustn't tread 	I mustn't be treading
you mustn't be treading
he mustn't be treading
we mustn't be treading
you mustn't be treading
they mustn't be treading	I mustn't have trod, trodden
you mustn't have trod, trodden
he mustn't have trod, trodden
we mustn't have trod, trodden
you mustn't have trod, trodden
they mustn't have trod, trodden	I mustn't have been treading
you mustn't have been treading
he mustn't have been treading
we mustn't have been treading
you mustn't have been treading
they mustn't have been treading	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I tread?
must you tread?
must he tread?
must we tread?
must you tread?
must they tread? 	must I be treading?
must you be treading?
must he be treading?
must we be treading?
must you be treading?
must they be treading? 	must I have trod, trodden?
must you have trod, trodden?
must he have trod, trodden?
must we have trod, trodden?
must you have trod, trodden?
must they have trod, trodden? 	must I have been treading?
must you have been treading?
must he have been treading?
must we have been treading?
must you have been treading?
must they have been treading? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I tread?
mustn't you tread?
mustn't he tread?
mustn't we tread?
mustn't you tread?
mustn't they tread? 	mustn't I be treading?
mustn't you be treading?
mustn't he be treading?
mustn't we be treading?
mustn't you be treading?
mustn't they be treading? 	mustn't I have trod, trodden?
mustn't you have trod, trodden?
mustn't he have trod, trodden?
mustn't we have trod, trodden?
mustn't you have trod, trodden?
mustn't they have trod, trodden? 	mustn't I have been treading?
mustn't you have been treading?
mustn't he have been treading?
mustn't we have been treading?
mustn't you have been treading?
mustn't they have been treading?