I must pick you must pick he must pick we must pick you must pick they must pick
V-ing form
I must be picking you must be picking he must be picking we must be picking you must be picking they must be picking
Perfect
I must have picked you must have picked he must have picked we must have picked you must have picked they must have picked
V-ing perfect
I must have been picking you must have been picking he must have been picking we must have been picking you must have been picking they must have been picking
Negation
Simple form
I must not pick you must not pick he must not pick we must not pick you must not pick they must not pick
V-ing form
I must not be picking you must not be picking he must not be picking we must not be picking you must not be picking they must not be picking
Perfect
I must not have picked you must not have picked he must not have picked we must not have picked you must not have picked they must not have picked
V-ing perfect
I must not have been picking you must not have been picking he must not have been picking we must not have been picking you must not have been picking they must not have been picking
Interrogative form
Simple form
must I pick? must you pick? must he pick? must we pick? must you pick? must they pick?
V-ing form
must I be picking? must you be picking? must he be picking? must we be picking? must you be picking? must they be picking?
Perfect
must I have picked? must you have picked? must he have picked? must we have picked? must you have picked? must they have picked?
V-ing perfect
must I have been picking? must you have been picking? must he have been picking? must we have been picking? must you have been picking? must they have been picking?
Interro-negative form
Simple form
must I not pick? must you not pick? must he not pick? must we not pick? must you not pick? must they not pick?
V-ing form
must I not be picking? must you not be picking? must he not be picking? must we not be picking? must you not be picking? must they not be picking?
Perfect
must I not have picked? must you not have picked? must he not have picked? must we not have picked? must you not have picked? must they not have picked?
V-ing perfect
must I not have been picking? must you not have been picking? must he not have been picking? must we not have been picking? must you not have been picking? must they not have been picking?