How to use 'MUST' in sentences as an Auxiliary Verb?
 In the series of learning medical transcription course , we dealt about ' WOULD ' usage in the prior lesson. Now we will study about the use of MUST as an auxiliary verb in English grammar.  Uses of  ‘must’: 1. Must is used as an auxiliary to show duty or  obligation (Here ‘must’ is stronger than ‘should’) 2. Must is used in future in  the past tense. Let us come to know certain rules which is used in the tense of  auxiliary form of the verb. A. In the simple present tense form the auxiliary  ‘must’ is used in the present form of the verb. B. In the present continuous  tense form the auxiliary ‘mustbe’ is used in the present form ending with –ING.  C. In the future in the past tense the auxiliary ‘must have’ is used in the past  participle form. D. In the future in the past continuous tense ‘must have been’  is used in the present form ending in –ing.          Whenever the structure of the  sentence expresses duty or obligation, the structures is shown as below  examples: 1. ...