Explanations

  1. (c) The normal word order for a clause is Subject/Verb/Object(s). The position of the circumstances surrounding the event or events is more flexible in English. The statement could begin or end with the circumstances
    eg Late last night (circumstances) the police (subject) captured (verb) the criminal (object).
    OR: The police (subject) captured (verb) the criminal (object) late last night. (circumstances)
    Remember that not all clauses need an object
    eg It (subject) rained (verb) very hard (circumstances) yesterday afternoon (circumstances)
    OR: Yesterday afternoon (circs) it (subj) rained (verb) very hard. (circs)
  2. (b) A verb is needed in order for a clause or a sentence to be complete. There can be one-word clauses (or simple sentences) in commands consisting of a single verb.
  3. (c) The subject (you) is implied in this command and not expressed. "You" are being ordered to keep off the grass.
  4. (b) This is a question, with the interrogative (question word) "what" at the beginning.
  5. (a) This is a statement with the normal word order for a clause or simple sentence - subject/verb/object
  6. (d) This is an exclamation, where the normal word order is changed for added emphasis. A statement would be written (or spoken) as:
    Time (subject) flies (verb) quickly (circumstances).
  7. (c) This is a single-word clause (or simple sentence), consisting of the verb "Halt!"
  8. (b) This is a question with the interrogative pronoun (question word), at the beginning of the clause (sentence).