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