I must strike you must strike he must strike we must strike you must strike they must strike
V-ing form
I must be striking you must be striking he must be striking we must be striking you must be striking they must be striking
Perfect
I must have struck, stricken you must have struck, stricken he must have struck, stricken we must have struck, stricken you must have struck, stricken they must have struck, stricken
V-ing perfect
I must have been striking you must have been striking he must have been striking we must have been striking you must have been striking they must have been striking
Negation
Simple form
I mustn't strike you mustn't strike he mustn't strike we mustn't strike you mustn't strike they mustn't strike
V-ing form
I mustn't be striking you mustn't be striking he mustn't be striking we mustn't be striking you mustn't be striking they mustn't be striking
Perfect
I mustn't have struck, stricken you mustn't have struck, stricken he mustn't have struck, stricken we mustn't have struck, stricken you mustn't have struck, stricken they mustn't have struck, stricken
V-ing perfect
I mustn't have been striking you mustn't have been striking he mustn't have been striking we mustn't have been striking you mustn't have been striking they mustn't have been striking
Interrogative form
Simple form
must I strike? must you strike? must he strike? must we strike? must you strike? must they strike?
V-ing form
must I be striking? must you be striking? must he be striking? must we be striking? must you be striking? must they be striking?
Perfect
must I have struck, stricken? must you have struck, stricken? must he have struck, stricken? must we have struck, stricken? must you have struck, stricken? must they have struck, stricken?
V-ing perfect
must I have been striking? must you have been striking? must he have been striking? must we have been striking? must you have been striking? must they have been striking?
Interro-negative form
Simple form
mustn't I strike? mustn't you strike? mustn't he strike? mustn't we strike? mustn't you strike? mustn't they strike?
V-ing form
mustn't I be striking? mustn't you be striking? mustn't he be striking? mustn't we be striking? mustn't you be striking? mustn't they be striking?
Perfect
mustn't I have struck, stricken? mustn't you have struck, stricken? mustn't he have struck, stricken? mustn't we have struck, stricken? mustn't you have struck, stricken? mustn't they have struck, stricken?
V-ing perfect
mustn't I have been striking? mustn't you have been striking? mustn't he have been striking? mustn't we have been striking? mustn't you have been striking? mustn't they have been striking?