must research
Verbe régulier : research - researched- researched
Traduction française : faire des recherches sur - faire des recherches ou de la recherche 

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must research
you must research
she must research
we must research
you must research
they must research 	I must be researching
you must be researching
she must be researching
we must be researching
you must be researching
they must be researching	I must have researched
you must have researched
she must have researched
we must have researched
you must have researched
they must have researched	I must have been researching
you must have been researching
she must have been researching
we must have been researching
you must have been researching
they must have been researching	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't research
you mustn't research
she mustn't research
we mustn't research
you mustn't research
they mustn't research 	I mustn't be researching
you mustn't be researching
she mustn't be researching
we mustn't be researching
you mustn't be researching
they mustn't be researching	I mustn't have researched
you mustn't have researched
she mustn't have researched
we mustn't have researched
you mustn't have researched
they mustn't have researched	I mustn't have been researching
you mustn't have been researching
she mustn't have been researching
we mustn't have been researching
you mustn't have been researching
they mustn't have been researching	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I research?
must you research?
must she research?
must we research?
must you research?
must they research? 	must I be researching?
must you be researching?
must she be researching?
must we be researching?
must you be researching?
must they be researching? 	must I have researched?
must you have researched?
must she have researched?
must we have researched?
must you have researched?
must they have researched? 	must I have been researching?
must you have been researching?
must she have been researching?
must we have been researching?
must you have been researching?
must they have been researching? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I research?
mustn't you research?
mustn't she research?
mustn't we research?
mustn't you research?
mustn't they research? 	mustn't I be researching?
mustn't you be researching?
mustn't she be researching?
mustn't we be researching?
mustn't you be researching?
mustn't they be researching? 	mustn't I have researched?
mustn't you have researched?
mustn't she have researched?
mustn't we have researched?
mustn't you have researched?
mustn't they have researched? 	mustn't I have been researching?
mustn't you have been researching?
mustn't she have been researching?
mustn't we have been researching?
mustn't you have been researching?
mustn't they have been researching?