must respire
Regular verb: respire - respired- respired

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must respire
you must respire
he must respire
we must respire
you must respire
they must respire 	I must be respiring
you must be respiring
he must be respiring
we must be respiring
you must be respiring
they must be respiring	I must have respired
you must have respired
he must have respired
we must have respired
you must have respired
they must have respired	I must have been respiring
you must have been respiring
he must have been respiring
we must have been respiring
you must have been respiring
they must have been respiring	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't respire
you mustn't respire
he mustn't respire
we mustn't respire
you mustn't respire
they mustn't respire 	I mustn't be respiring
you mustn't be respiring
he mustn't be respiring
we mustn't be respiring
you mustn't be respiring
they mustn't be respiring	I mustn't have respired
you mustn't have respired
he mustn't have respired
we mustn't have respired
you mustn't have respired
they mustn't have respired	I mustn't have been respiring
you mustn't have been respiring
he mustn't have been respiring
we mustn't have been respiring
you mustn't have been respiring
they mustn't have been respiring	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I respire?
must you respire?
must he respire?
must we respire?
must you respire?
must they respire? 	must I be respiring?
must you be respiring?
must he be respiring?
must we be respiring?
must you be respiring?
must they be respiring? 	must I have respired?
must you have respired?
must he have respired?
must we have respired?
must you have respired?
must they have respired? 	must I have been respiring?
must you have been respiring?
must he have been respiring?
must we have been respiring?
must you have been respiring?
must they have been respiring? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I respire?
mustn't you respire?
mustn't he respire?
mustn't we respire?
mustn't you respire?
mustn't they respire? 	mustn't I be respiring?
mustn't you be respiring?
mustn't he be respiring?
mustn't we be respiring?
mustn't you be respiring?
mustn't they be respiring? 	mustn't I have respired?
mustn't you have respired?
mustn't he have respired?
mustn't we have respired?
mustn't you have respired?
mustn't they have respired? 	mustn't I have been respiring?
mustn't you have been respiring?
mustn't he have been respiring?
mustn't we have been respiring?
mustn't you have been respiring?
mustn't they have been respiring?