must fribble
Verbo regular: fribble - fribbled- fribbled

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must fribble
you must fribble
he must fribble
we must fribble
you must fribble
they must fribble 	I must be fribbling
you must be fribbling
he must be fribbling
we must be fribbling
you must be fribbling
they must be fribbling	I must have fribbled
you must have fribbled
he must have fribbled
we must have fribbled
you must have fribbled
they must have fribbled	I must have been fribbling
you must have been fribbling
he must have been fribbling
we must have been fribbling
you must have been fribbling
they must have been fribbling	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not fribble
you must not fribble
he must not fribble
we must not fribble
you must not fribble
they must not fribble 	I must not be fribbling
you must not be fribbling
he must not be fribbling
we must not be fribbling
you must not be fribbling
they must not be fribbling	I must not have fribbled
you must not have fribbled
he must not have fribbled
we must not have fribbled
you must not have fribbled
they must not have fribbled	I must not have been fribbling
you must not have been fribbling
he must not have been fribbling
we must not have been fribbling
you must not have been fribbling
they must not have been fribbling	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I fribble?
must you fribble?
must he fribble?
must we fribble?
must you fribble?
must they fribble? 	must I be fribbling?
must you be fribbling?
must he be fribbling?
must we be fribbling?
must you be fribbling?
must they be fribbling? 	must I have fribbled?
must you have fribbled?
must he have fribbled?
must we have fribbled?
must you have fribbled?
must they have fribbled? 	must I have been fribbling?
must you have been fribbling?
must he have been fribbling?
must we have been fribbling?
must you have been fribbling?
must they have been fribbling? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not fribble?
must you not fribble?
must he not fribble?
must we not fribble?
must you not fribble?
must they not fribble? 	must I not be fribbling?
must you not be fribbling?
must he not be fribbling?
must we not be fribbling?
must you not be fribbling?
must they not be fribbling? 	must I not have fribbled?
must you not have fribbled?
must he not have fribbled?
must we not have fribbled?
must you not have fribbled?
must they not have fribbled? 	must I not have been fribbling?
must you not have been fribbling?
must he not have been fribbling?
must we not have been fribbling?
must you not have been fribbling?
must they not have been fribbling?