I must soften you must soften she must soften we must soften you must soften they must soften
V-ing form
I must be softening you must be softening she must be softening we must be softening you must be softening they must be softening
Perfect
I must have softened you must have softened she must have softened we must have softened you must have softened they must have softened
V-ing perfect
I must have been softening you must have been softening she must have been softening we must have been softening you must have been softening they must have been softening
Negation
Simple form
I must not soften you must not soften she must not soften we must not soften you must not soften they must not soften
V-ing form
I must not be softening you must not be softening she must not be softening we must not be softening you must not be softening they must not be softening
Perfect
I must not have softened you must not have softened she must not have softened we must not have softened you must not have softened they must not have softened
V-ing perfect
I must not have been softening you must not have been softening she must not have been softening we must not have been softening you must not have been softening they must not have been softening
Interrogative form
Simple form
must I soften? must you soften? must she soften? must we soften? must you soften? must they soften?
V-ing form
must I be softening? must you be softening? must she be softening? must we be softening? must you be softening? must they be softening?
Perfect
must I have softened? must you have softened? must she have softened? must we have softened? must you have softened? must they have softened?
V-ing perfect
must I have been softening? must you have been softening? must she have been softening? must we have been softening? must you have been softening? must they have been softening?
Interro-negative form
Simple form
must I not soften? must you not soften? must she not soften? must we not soften? must you not soften? must they not soften?
V-ing form
must I not be softening? must you not be softening? must she not be softening? must we not be softening? must you not be softening? must they not be softening?
Perfect
must I not have softened? must you not have softened? must she not have softened? must we not have softened? must you not have softened? must they not have softened?
V-ing perfect
must I not have been softening? must you not have been softening? must she not have been softening? must we not have been softening? must you not have been softening? must they not have been softening?