I must fish you must fish she must fish we must fish you must fish they must fish
V-ing form
I must be fishing you must be fishing she must be fishing we must be fishing you must be fishing they must be fishing
Perfect
I must have fished you must have fished she must have fished we must have fished you must have fished they must have fished
V-ing perfect
I must have been fishing you must have been fishing she must have been fishing we must have been fishing you must have been fishing they must have been fishing
Negation
Simple form
I must not fish you must not fish she must not fish we must not fish you must not fish they must not fish
V-ing form
I must not be fishing you must not be fishing she must not be fishing we must not be fishing you must not be fishing they must not be fishing
Perfect
I must not have fished you must not have fished she must not have fished we must not have fished you must not have fished they must not have fished
V-ing perfect
I must not have been fishing you must not have been fishing she must not have been fishing we must not have been fishing you must not have been fishing they must not have been fishing
Interrogative form
Simple form
must I fish? must you fish? must she fish? must we fish? must you fish? must they fish?
V-ing form
must I be fishing? must you be fishing? must she be fishing? must we be fishing? must you be fishing? must they be fishing?
Perfect
must I have fished? must you have fished? must she have fished? must we have fished? must you have fished? must they have fished?
V-ing perfect
must I have been fishing? must you have been fishing? must she have been fishing? must we have been fishing? must you have been fishing? must they have been fishing?
Interro-negative form
Simple form
must I not fish? must you not fish? must she not fish? must we not fish? must you not fish? must they not fish?
V-ing form
must I not be fishing? must you not be fishing? must she not be fishing? must we not be fishing? must you not be fishing? must they not be fishing?
Perfect
must I not have fished? must you not have fished? must she not have fished? must we not have fished? must you not have fished? must they not have fished?
V-ing perfect
must I not have been fishing? must you not have been fishing? must she not have been fishing? must we not have been fishing? must you not have been fishing? must they not have been fishing?