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