must combine
Verbo regular: combine - combined- combined

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must combine
you must combine
he must combine
we must combine
you must combine
they must combine 	I must be combining
you must be combining
he must be combining
we must be combining
you must be combining
they must be combining	I must have combined
you must have combined
he must have combined
we must have combined
you must have combined
they must have combined	I must have been combining
you must have been combining
he must have been combining
we must have been combining
you must have been combining
they must have been combining	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not combine
you must not combine
he must not combine
we must not combine
you must not combine
they must not combine 	I must not be combining
you must not be combining
he must not be combining
we must not be combining
you must not be combining
they must not be combining	I must not have combined
you must not have combined
he must not have combined
we must not have combined
you must not have combined
they must not have combined	I must not have been combining
you must not have been combining
he must not have been combining
we must not have been combining
you must not have been combining
they must not have been combining	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I combine?
must you combine?
must he combine?
must we combine?
must you combine?
must they combine? 	must I be combining?
must you be combining?
must he be combining?
must we be combining?
must you be combining?
must they be combining? 	must I have combined?
must you have combined?
must he have combined?
must we have combined?
must you have combined?
must they have combined? 	must I have been combining?
must you have been combining?
must he have been combining?
must we have been combining?
must you have been combining?
must they have been combining? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not combine?
must you not combine?
must he not combine?
must we not combine?
must you not combine?
must they not combine? 	must I not be combining?
must you not be combining?
must he not be combining?
must we not be combining?
must you not be combining?
must they not be combining? 	must I not have combined?
must you not have combined?
must he not have combined?
must we not have combined?
must you not have combined?
must they not have combined? 	must I not have been combining?
must you not have been combining?
must he not have been combining?
must we not have been combining?
must you not have been combining?
must they not have been combining?