must titter
Verbe régulier : titter - tittered- tittered
Traduction française : rire bêtement ou sottement - glousser 

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must titter
you must titter
he must titter
we must titter
you must titter
they must titter 	I must be tittering
you must be tittering
he must be tittering
we must be tittering
you must be tittering
they must be tittering	I must have tittered
you must have tittered
he must have tittered
we must have tittered
you must have tittered
they must have tittered	I must have been tittering
you must have been tittering
he must have been tittering
we must have been tittering
you must have been tittering
they must have been tittering	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't titter
you mustn't titter
he mustn't titter
we mustn't titter
you mustn't titter
they mustn't titter 	I mustn't be tittering
you mustn't be tittering
he mustn't be tittering
we mustn't be tittering
you mustn't be tittering
they mustn't be tittering	I mustn't have tittered
you mustn't have tittered
he mustn't have tittered
we mustn't have tittered
you mustn't have tittered
they mustn't have tittered	I mustn't have been tittering
you mustn't have been tittering
he mustn't have been tittering
we mustn't have been tittering
you mustn't have been tittering
they mustn't have been tittering	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I titter?
must you titter?
must he titter?
must we titter?
must you titter?
must they titter? 	must I be tittering?
must you be tittering?
must he be tittering?
must we be tittering?
must you be tittering?
must they be tittering? 	must I have tittered?
must you have tittered?
must he have tittered?
must we have tittered?
must you have tittered?
must they have tittered? 	must I have been tittering?
must you have been tittering?
must he have been tittering?
must we have been tittering?
must you have been tittering?
must they have been tittering? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I titter?
mustn't you titter?
mustn't he titter?
mustn't we titter?
mustn't you titter?
mustn't they titter? 	mustn't I be tittering?
mustn't you be tittering?
mustn't he be tittering?
mustn't we be tittering?
mustn't you be tittering?
mustn't they be tittering? 	mustn't I have tittered?
mustn't you have tittered?
mustn't he have tittered?
mustn't we have tittered?
mustn't you have tittered?
mustn't they have tittered? 	mustn't I have been tittering?
mustn't you have been tittering?
mustn't he have been tittering?
mustn't we have been tittering?
mustn't you have been tittering?
mustn't they have been tittering?