I must founder you must founder he must founder we must founder you must founder they must founder
Forme en V-ing
I must be foundering you must be foundering he must be foundering we must be foundering you must be foundering they must be foundering
Perfect
I must have foundered you must have foundered he must have foundered we must have foundered you must have foundered they must have foundered
Perfect en V-ing
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
Négation
Forme simple
I mustn't founder you mustn't founder he mustn't founder we mustn't founder you mustn't founder they mustn't founder
Forme en V-ing
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
Perfect
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
Perfect en V-ing
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
Forme interrogative
Forme simple
must I founder? must you founder? must he founder? must we founder? must you founder? must they founder?
Forme en V-ing
must I be foundering? must you be foundering? must he be foundering? must we be foundering? must you be foundering? must they be foundering?
Perfect
must I have foundered? must you have foundered? must he have foundered? must we have foundered? must you have foundered? must they have foundered?
Perfect en V-ing
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?
Forme interro-négative
Forme simple
mustn't I founder? mustn't you founder? mustn't he founder? mustn't we founder? mustn't you founder? mustn't they founder?
Forme en V-ing
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?
Perfect
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?
Perfect en V-ing
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?