I must interlock you must interlock he must interlock we must interlock you must interlock they must interlock
V-ing form
I must be interlocking you must be interlocking he must be interlocking we must be interlocking you must be interlocking they must be interlocking
Perfect
I must have interlocked you must have interlocked he must have interlocked we must have interlocked you must have interlocked they must have interlocked
V-ing perfect
I must have been interlocking you must have been interlocking he must have been interlocking we must have been interlocking you must have been interlocking they must have been interlocking
Negation
Simple form
I mustn't interlock you mustn't interlock he mustn't interlock we mustn't interlock you mustn't interlock they mustn't interlock
V-ing form
I mustn't be interlocking you mustn't be interlocking he mustn't be interlocking we mustn't be interlocking you mustn't be interlocking they mustn't be interlocking
Perfect
I mustn't have interlocked you mustn't have interlocked he mustn't have interlocked we mustn't have interlocked you mustn't have interlocked they mustn't have interlocked
V-ing perfect
I mustn't have been interlocking you mustn't have been interlocking he mustn't have been interlocking we mustn't have been interlocking you mustn't have been interlocking they mustn't have been interlocking
Interrogative form
Simple form
must I interlock? must you interlock? must he interlock? must we interlock? must you interlock? must they interlock?
V-ing form
must I be interlocking? must you be interlocking? must he be interlocking? must we be interlocking? must you be interlocking? must they be interlocking?
Perfect
must I have interlocked? must you have interlocked? must he have interlocked? must we have interlocked? must you have interlocked? must they have interlocked?
V-ing perfect
must I have been interlocking? must you have been interlocking? must he have been interlocking? must we have been interlocking? must you have been interlocking? must they have been interlocking?
Interro-negative form
Simple form
mustn't I interlock? mustn't you interlock? mustn't he interlock? mustn't we interlock? mustn't you interlock? mustn't they interlock?
V-ing form
mustn't I be interlocking? mustn't you be interlocking? mustn't he be interlocking? mustn't we be interlocking? mustn't you be interlocking? mustn't they be interlocking?
Perfect
mustn't I have interlocked? mustn't you have interlocked? mustn't he have interlocked? mustn't we have interlocked? mustn't you have interlocked? mustn't they have interlocked?
V-ing perfect
mustn't I have been interlocking? mustn't you have been interlocking? mustn't he have been interlocking? mustn't we have been interlocking? mustn't you have been interlocking? mustn't they have been interlocking?