Here's a detailed explanation of each primary auxiliary verb:

1. "Be":

   • "Be" is used to form continuous tenses and the passive voice.
   • Examples:
     • Continuous Tenses:
       • "She is studying for her exams." (present continuous)
       • "They were playing soccer in the park." (past continuous)
     • Passive Voice:
       • "The book was written by him." (past simple passive)
       • "The cake is being baked in the oven." (present continuous passive)

2. "Have":

   • "Have" is used to form perfect tenses.
   • Examples:
     • "I have finished my work." (present perfect)
     • "They had already left when I arrived." (past perfect)
     • "She will have completed the project by tomorrow." (future perfect)

3. "Do":

   • "Do" is used to form questions and negative sentences in the present simple and past simple.
   • Examples:
     • Questions:
       • "Do you like ice cream?" (present simple)
       • "Did they go to the party?" (past simple)
     • Negative Sentences:
       • "I do not understand the instructions." (present simple)
       • "They did not finish their homework." (past simple)

Primary auxiliary verbs work together with the main verb to create different verb forms and express specific aspects of the action or state. They are essential for constructing sentences with proper tense, question forms, negative forms, and passive voice. Understanding and using primary auxiliary verbs correctly contributes to clear and accurate communication in English.