must founder
Verbo regular: founder - foundered- foundered

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must founder
you must founder
he must founder
we must founder
you must founder
they must founder 	I must be foundering
you must be foundering
he must be foundering
we must be foundering
you must be foundering
they must be foundering	I must have foundered
you must have foundered
he must have foundered
we must have foundered
you must have foundered
they must have foundered	I must have been foundering
you must have been foundering
he must have been foundering
we must have been foundering
you must have been foundering
they must have been foundering	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't founder
you mustn't founder
he mustn't founder
we mustn't founder
you mustn't founder
they mustn't founder 	I mustn't be foundering
you mustn't be foundering
he mustn't be foundering
we mustn't be foundering
you mustn't be foundering
they mustn't be foundering	I mustn't have foundered
you mustn't have foundered
he mustn't have foundered
we mustn't have foundered
you mustn't have foundered
they mustn't have foundered	I mustn't have been foundering
you mustn't have been foundering
he mustn't have been foundering
we mustn't have been foundering
you mustn't have been foundering
they mustn't have been foundering	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I founder?
must you founder?
must he founder?
must we founder?
must you founder?
must they founder? 	must I be foundering?
must you be foundering?
must he be foundering?
must we be foundering?
must you be foundering?
must they be foundering? 	must I have foundered?
must you have foundered?
must he have foundered?
must we have foundered?
must you have foundered?
must they have foundered? 	must I have been foundering?
must you have been foundering?
must he have been foundering?
must we have been foundering?
must you have been foundering?
must they have been foundering? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I founder?
mustn't you founder?
mustn't he founder?
mustn't we founder?
mustn't you founder?
mustn't they founder? 	mustn't I be foundering?
mustn't you be foundering?
mustn't he be foundering?
mustn't we be foundering?
mustn't you be foundering?
mustn't they be foundering? 	mustn't I have foundered?
mustn't you have foundered?
mustn't he have foundered?
mustn't we have foundered?
mustn't you have foundered?
mustn't they have foundered? 	mustn't I have been foundering?
mustn't you have been foundering?
mustn't he have been foundering?
mustn't we have been foundering?
mustn't you have been foundering?
mustn't they have been foundering?