I must refrigerate you must refrigerate he must refrigerate we must refrigerate you must refrigerate they must refrigerate
V-ing form
I must be refrigerating you must be refrigerating he must be refrigerating we must be refrigerating you must be refrigerating they must be refrigerating
Perfect
I must have refrigerated you must have refrigerated he must have refrigerated we must have refrigerated you must have refrigerated they must have refrigerated
V-ing perfect
I must have been refrigerating you must have been refrigerating he must have been refrigerating we must have been refrigerating you must have been refrigerating they must have been refrigerating
Negation
Simple form
I must not refrigerate you must not refrigerate he must not refrigerate we must not refrigerate you must not refrigerate they must not refrigerate
V-ing form
I must not be refrigerating you must not be refrigerating he must not be refrigerating we must not be refrigerating you must not be refrigerating they must not be refrigerating
Perfect
I must not have refrigerated you must not have refrigerated he must not have refrigerated we must not have refrigerated you must not have refrigerated they must not have refrigerated
V-ing perfect
I must not have been refrigerating you must not have been refrigerating he must not have been refrigerating we must not have been refrigerating you must not have been refrigerating they must not have been refrigerating
Interrogative form
Simple form
must I refrigerate? must you refrigerate? must he refrigerate? must we refrigerate? must you refrigerate? must they refrigerate?
V-ing form
must I be refrigerating? must you be refrigerating? must he be refrigerating? must we be refrigerating? must you be refrigerating? must they be refrigerating?
Perfect
must I have refrigerated? must you have refrigerated? must he have refrigerated? must we have refrigerated? must you have refrigerated? must they have refrigerated?
V-ing perfect
must I have been refrigerating? must you have been refrigerating? must he have been refrigerating? must we have been refrigerating? must you have been refrigerating? must they have been refrigerating?
Interro-negative form
Simple form
must I not refrigerate? must you not refrigerate? must he not refrigerate? must we not refrigerate? must you not refrigerate? must they not refrigerate?
V-ing form
must I not be refrigerating? must you not be refrigerating? must he not be refrigerating? must we not be refrigerating? must you not be refrigerating? must they not be refrigerating?
Perfect
must I not have refrigerated? must you not have refrigerated? must he not have refrigerated? must we not have refrigerated? must you not have refrigerated? must they not have refrigerated?
V-ing perfect
must I not have been refrigerating? must you not have been refrigerating? must he not have been refrigerating? must we not have been refrigerating? must you not have been refrigerating? must they not have been refrigerating?