I must sting you must sting she must sting we must sting you must sting they must sting
V-ing form
I must be stinging you must be stinging she must be stinging we must be stinging you must be stinging they must be stinging
Perfect
I must have stung you must have stung she must have stung we must have stung you must have stung they must have stung
V-ing perfect
I must have been stinging you must have been stinging she must have been stinging we must have been stinging you must have been stinging they must have been stinging
Negation
Simple form
I mustn't sting you mustn't sting she mustn't sting we mustn't sting you mustn't sting they mustn't sting
V-ing form
I mustn't be stinging you mustn't be stinging she mustn't be stinging we mustn't be stinging you mustn't be stinging they mustn't be stinging
Perfect
I mustn't have stung you mustn't have stung she mustn't have stung we mustn't have stung you mustn't have stung they mustn't have stung
V-ing perfect
I mustn't have been stinging you mustn't have been stinging she mustn't have been stinging we mustn't have been stinging you mustn't have been stinging they mustn't have been stinging
Interrogative form
Simple form
must I sting? must you sting? must she sting? must we sting? must you sting? must they sting?
V-ing form
must I be stinging? must you be stinging? must she be stinging? must we be stinging? must you be stinging? must they be stinging?
Perfect
must I have stung? must you have stung? must she have stung? must we have stung? must you have stung? must they have stung?
V-ing perfect
must I have been stinging? must you have been stinging? must she have been stinging? must we have been stinging? must you have been stinging? must they have been stinging?
Interro-negative form
Simple form
mustn't I sting? mustn't you sting? mustn't she sting? mustn't we sting? mustn't you sting? mustn't they sting?
V-ing form
mustn't I be stinging? mustn't you be stinging? mustn't she be stinging? mustn't we be stinging? mustn't you be stinging? mustn't they be stinging?
Perfect
mustn't I have stung? mustn't you have stung? mustn't she have stung? mustn't we have stung? mustn't you have stung? mustn't they have stung?
V-ing perfect
mustn't I have been stinging? mustn't you have been stinging? mustn't she have been stinging? mustn't we have been stinging? mustn't you have been stinging? mustn't they have been stinging?