I must learn you must learn he must learn we must learn you must learn they must learn
V-ing form
I must be learning you must be learning he must be learning we must be learning you must be learning they must be learning
Perfect
I must have learned, learnt you must have learned, learnt he must have learned, learnt we must have learned, learnt you must have learned, learnt they must have learned, learnt
V-ing perfect
I must have been learning you must have been learning he must have been learning we must have been learning you must have been learning they must have been learning
Negation
Simple form
I must not learn you must not learn he must not learn we must not learn you must not learn they must not learn
V-ing form
I must not be learning you must not be learning he must not be learning we must not be learning you must not be learning they must not be learning
Perfect
I must not have learned, learnt you must not have learned, learnt he must not have learned, learnt we must not have learned, learnt you must not have learned, learnt they must not have learned, learnt
V-ing perfect
I must not have been learning you must not have been learning he must not have been learning we must not have been learning you must not have been learning they must not have been learning
Interrogative form
Simple form
must I learn? must you learn? must he learn? must we learn? must you learn? must they learn?
V-ing form
must I be learning? must you be learning? must he be learning? must we be learning? must you be learning? must they be learning?
Perfect
must I have learned, learnt? must you have learned, learnt? must he have learned, learnt? must we have learned, learnt? must you have learned, learnt? must they have learned, learnt?
V-ing perfect
must I have been learning? must you have been learning? must he have been learning? must we have been learning? must you have been learning? must they have been learning?
Interro-negative form
Simple form
must I not learn? must you not learn? must he not learn? must we not learn? must you not learn? must they not learn?
V-ing form
must I not be learning? must you not be learning? must he not be learning? must we not be learning? must you not be learning? must they not be learning?
Perfect
must I not have learned, learnt? must you not have learned, learnt? must he not have learned, learnt? must we not have learned, learnt? must you not have learned, learnt? must they not have learned, learnt?
V-ing perfect
must I not have been learning? must you not have been learning? must he not have been learning? must we not have been learning? must you not have been learning? must they not have been learning?