I must discover you must discover she must discover we must discover you must discover they must discover
V-ing form
I must be discovering you must be discovering she must be discovering we must be discovering you must be discovering they must be discovering
Perfect
I must have discovered you must have discovered she must have discovered we must have discovered you must have discovered they must have discovered
V-ing perfect
I must have been discovering you must have been discovering she must have been discovering we must have been discovering you must have been discovering they must have been discovering
Negation
Simple form
I must not discover you must not discover she must not discover we must not discover you must not discover they must not discover
V-ing form
I must not be discovering you must not be discovering she must not be discovering we must not be discovering you must not be discovering they must not be discovering
Perfect
I must not have discovered you must not have discovered she must not have discovered we must not have discovered you must not have discovered they must not have discovered
V-ing perfect
I must not have been discovering you must not have been discovering she must not have been discovering we must not have been discovering you must not have been discovering they must not have been discovering
Interrogative form
Simple form
must I discover? must you discover? must she discover? must we discover? must you discover? must they discover?
V-ing form
must I be discovering? must you be discovering? must she be discovering? must we be discovering? must you be discovering? must they be discovering?
Perfect
must I have discovered? must you have discovered? must she have discovered? must we have discovered? must you have discovered? must they have discovered?
V-ing perfect
must I have been discovering? must you have been discovering? must she have been discovering? must we have been discovering? must you have been discovering? must they have been discovering?
Interro-negative form
Simple form
must I not discover? must you not discover? must she not discover? must we not discover? must you not discover? must they not discover?
V-ing form
must I not be discovering? must you not be discovering? must she not be discovering? must we not be discovering? must you not be discovering? must they not be discovering?
Perfect
must I not have discovered? must you not have discovered? must she not have discovered? must we not have discovered? must you not have discovered? must they not have discovered?
V-ing perfect
must I not have been discovering? must you not have been discovering? must she not have been discovering? must we not have been discovering? must you not have been discovering? must they not have been discovering?