I must shudder you must shudder she must shudder we must shudder you must shudder they must shudder
V-ing form
I must be shuddering you must be shuddering she must be shuddering we must be shuddering you must be shuddering they must be shuddering
Perfect
I must have shuddered you must have shuddered she must have shuddered we must have shuddered you must have shuddered they must have shuddered
V-ing perfect
I must have been shuddering you must have been shuddering she must have been shuddering we must have been shuddering you must have been shuddering they must have been shuddering
Negation
Simple form
I must not shudder you must not shudder she must not shudder we must not shudder you must not shudder they must not shudder
V-ing form
I must not be shuddering you must not be shuddering she must not be shuddering we must not be shuddering you must not be shuddering they must not be shuddering
Perfect
I must not have shuddered you must not have shuddered she must not have shuddered we must not have shuddered you must not have shuddered they must not have shuddered
V-ing perfect
I must not have been shuddering you must not have been shuddering she must not have been shuddering we must not have been shuddering you must not have been shuddering they must not have been shuddering
Interrogative form
Simple form
must I shudder? must you shudder? must she shudder? must we shudder? must you shudder? must they shudder?
V-ing form
must I be shuddering? must you be shuddering? must she be shuddering? must we be shuddering? must you be shuddering? must they be shuddering?
Perfect
must I have shuddered? must you have shuddered? must she have shuddered? must we have shuddered? must you have shuddered? must they have shuddered?
V-ing perfect
must I have been shuddering? must you have been shuddering? must she have been shuddering? must we have been shuddering? must you have been shuddering? must they have been shuddering?
Interro-negative form
Simple form
must I not shudder? must you not shudder? must she not shudder? must we not shudder? must you not shudder? must they not shudder?
V-ing form
must I not be shuddering? must you not be shuddering? must she not be shuddering? must we not be shuddering? must you not be shuddering? must they not be shuddering?
Perfect
must I not have shuddered? must you not have shuddered? must she not have shuddered? must we not have shuddered? must you not have shuddered? must they not have shuddered?
V-ing perfect
must I not have been shuddering? must you not have been shuddering? must she not have been shuddering? must we not have been shuddering? must you not have been shuddering? must they not have been shuddering?