13.1   Conjunctions
   13.1.1   Definition
   13.1.2   Types of Conjunctions 
       13.1.2.1   Coordinating Conjunctions 
       13.1.2.2   Subordinating Conjunctions
       13.1.2.3   Correlative Conjunctions
   13.1.3   When, while, as
   13.1.4   List of Conjunctions
13.2   Interjections
     13.2.1   Definition
     13.2.2   Interjections and examples
     13.2.3   List of Interjections