I must breakfast you must breakfast he must breakfast we must breakfast you must breakfast they must breakfast
V-ing form
I must be breakfasting you must be breakfasting he must be breakfasting we must be breakfasting you must be breakfasting they must be breakfasting
Perfect
I must have breakfasted you must have breakfasted he must have breakfasted we must have breakfasted you must have breakfasted they must have breakfasted
V-ing perfect
I must have been breakfasting you must have been breakfasting he must have been breakfasting we must have been breakfasting you must have been breakfasting they must have been breakfasting
Negation
Simple form
I must not breakfast you must not breakfast he must not breakfast we must not breakfast you must not breakfast they must not breakfast
V-ing form
I must not be breakfasting you must not be breakfasting he must not be breakfasting we must not be breakfasting you must not be breakfasting they must not be breakfasting
Perfect
I must not have breakfasted you must not have breakfasted he must not have breakfasted we must not have breakfasted you must not have breakfasted they must not have breakfasted
V-ing perfect
I must not have been breakfasting you must not have been breakfasting he must not have been breakfasting we must not have been breakfasting you must not have been breakfasting they must not have been breakfasting
Interrogative form
Simple form
must I breakfast? must you breakfast? must he breakfast? must we breakfast? must you breakfast? must they breakfast?
V-ing form
must I be breakfasting? must you be breakfasting? must he be breakfasting? must we be breakfasting? must you be breakfasting? must they be breakfasting?
Perfect
must I have breakfasted? must you have breakfasted? must he have breakfasted? must we have breakfasted? must you have breakfasted? must they have breakfasted?
V-ing perfect
must I have been breakfasting? must you have been breakfasting? must he have been breakfasting? must we have been breakfasting? must you have been breakfasting? must they have been breakfasting?
Interro-negative form
Simple form
must I not breakfast? must you not breakfast? must he not breakfast? must we not breakfast? must you not breakfast? must they not breakfast?
V-ing form
must I not be breakfasting? must you not be breakfasting? must he not be breakfasting? must we not be breakfasting? must you not be breakfasting? must they not be breakfasting?
Perfect
must I not have breakfasted? must you not have breakfasted? must he not have breakfasted? must we not have breakfasted? must you not have breakfasted? must they not have breakfasted?
V-ing perfect
must I not have been breakfasting? must you not have been breakfasting? must he not have been breakfasting? must we not have been breakfasting? must you not have been breakfasting? must they not have been breakfasting?