English verb conjugation
MUST RESEARCH

Regular verb: research - researched - researched

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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

Negation

Simple form	V-ing form
I mustn't research you mustn't research he 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 he mustn't be researching we mustn't be researching you mustn't be researching they mustn't be researching
Perfect	V-ing perfect
I mustn't have researched you mustn't have researched he 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 he mustn't have been researching we mustn't have been researching you mustn't have been researching they mustn't have been researching

Interrogative form

Simple form	V-ing form
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?
Perfect	V-ing perfect
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?

Interro-negative form

Simple form	V-ing form
mustn't I research? mustn't you research? mustn't he 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 he be researching? mustn't we be researching? mustn't you be researching? mustn't they be researching?
Perfect	V-ing perfect
mustn't I have researched? mustn't you have researched? mustn't he 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 he have been researching? mustn't we have been researching? mustn't you have been researching? mustn't they have been researching?