I must buttress you must buttress he must buttress we must buttress you must buttress they must buttress
Forme en V-ing
I must be buttressing you must be buttressing he must be buttressing we must be buttressing you must be buttressing they must be buttressing
Perfect
I must have buttressed you must have buttressed he must have buttressed we must have buttressed you must have buttressed they must have buttressed
Perfect en V-ing
I must have been buttressing you must have been buttressing he must have been buttressing we must have been buttressing you must have been buttressing they must have been buttressing
Négation
Forme simple
I mustn't buttress you mustn't buttress he mustn't buttress we mustn't buttress you mustn't buttress they mustn't buttress
Forme en V-ing
I mustn't be buttressing you mustn't be buttressing he mustn't be buttressing we mustn't be buttressing you mustn't be buttressing they mustn't be buttressing
Perfect
I mustn't have buttressed you mustn't have buttressed he mustn't have buttressed we mustn't have buttressed you mustn't have buttressed they mustn't have buttressed
Perfect en V-ing
I mustn't have been buttressing you mustn't have been buttressing he mustn't have been buttressing we mustn't have been buttressing you mustn't have been buttressing they mustn't have been buttressing
Forme interrogative
Forme simple
must I buttress? must you buttress? must he buttress? must we buttress? must you buttress? must they buttress?
Forme en V-ing
must I be buttressing? must you be buttressing? must he be buttressing? must we be buttressing? must you be buttressing? must they be buttressing?
Perfect
must I have buttressed? must you have buttressed? must he have buttressed? must we have buttressed? must you have buttressed? must they have buttressed?
Perfect en V-ing
must I have been buttressing? must you have been buttressing? must he have been buttressing? must we have been buttressing? must you have been buttressing? must they have been buttressing?
Forme interro-négative
Forme simple
mustn't I buttress? mustn't you buttress? mustn't he buttress? mustn't we buttress? mustn't you buttress? mustn't they buttress?
Forme en V-ing
mustn't I be buttressing? mustn't you be buttressing? mustn't he be buttressing? mustn't we be buttressing? mustn't you be buttressing? mustn't they be buttressing?
Perfect
mustn't I have buttressed? mustn't you have buttressed? mustn't he have buttressed? mustn't we have buttressed? mustn't you have buttressed? mustn't they have buttressed?
Perfect en V-ing
mustn't I have been buttressing? mustn't you have been buttressing? mustn't he have been buttressing? mustn't we have been buttressing? mustn't you have been buttressing? mustn't they have been buttressing?