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
he must research
we must research
you must research
they must research 	I must be researching
you must be researching
he must be researching
we must be researching
you must be researching
they must be researching	I must have researched
you must have researched
he 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
he 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 must not research
you must not research
he must not research
we must not research
you must not research
they must not research 	I must not be researching
you must not be researching
he must not be researching
we must not be researching
you must not be researching
they must not be researching	I must not have researched
you must not have researched
he must not have researched
we must not have researched
you must not have researched
they must not have researched	I must not have been researching
you must not have been researching
he must not have been researching
we must not have been researching
you must not have been researching
they must not have been researching	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I research?
must you research?
must he research?
must we research?
must you research?
must they research? 	must I be researching?
must you be researching?
must he be researching?
must we be researching?
must you be researching?
must they be researching? 	must I have researched?
must you have researched?
must he 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 he 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 	
must I not research?
must you not research?
must he not research?
must we not research?
must you not research?
must they not research? 	must I not be researching?
must you not be researching?
must he not be researching?
must we not be researching?
must you not be researching?
must they not be researching? 	must I not have researched?
must you not have researched?
must he not have researched?
must we not have researched?
must you not have researched?
must they not have researched? 	must I not have been researching?
must you not have been researching?
must he not have been researching?
must we not have been researching?
must you not have been researching?
must they not have been researching?