Noun Clause 

In the dialog, the noun clause functions as an object or subject.
There are some kinds of noun clauses, such as the following :


1. Noun clauses which begin with that.
    a. As a subject.
        Here, we cannot omit the word 'that'.
        Examples :
        - Statement
        > Sugar is sweet. It is a fact.
        > The children speak English fluently. It is understandable.
     
        - Noun clause
        > That sugar is sweet is a fact.
        > That the children speak English fluently is understandable.

    b. As an object.
        Here, we can omit the word 'that'.
        Examples :
        - Statement
        > Danny is clever.
        > Reading is necessary.

        - Noun clause
        > I think (that) Danny is clever.
        > We know (that) reading is necessary.

2. Noun clauses which begin with whether/if.
    a. As a subject.
        Whether the man is tired or not is obvious.

    b. As an object
        As an object, the noun clause is formed from a yes/no question.
        Examples :
        - Yes/No Question
        > Is your father a lawyer ?
        > Do the children enjoy the game ?

        - Noun clause :
        > I wonder whether your father is a lawyer.
        > I don't know if the children enjoy the game.

3. Noun clauses which begin with a question word.
    a. As a subject.
        When the noun clause becomes a subject, the verb is singular.
        Example :
        What we will do tonight is not decided yet.

    b. As an object.
        Examples :
        - Wh - Question
        > Where do you study ?
        > Who is she ?
        > Who has the dictionary ?
     
        - Noun clause :
        > Please tell me where you study.
        > I don't remember who she is.
        > I don't know who has the dictionary.

My problem :
  I'm still confuse in wh-question and yes/no question. Because in wh-question and yes/no question there are   word do, does, is, are, etc.
  I don't know to place or not using it to the noun clause.
  Example of the sentences :
  - Is the table on discount ?
  - Where is my cat ?
  - Where does the girl go ?
  - Who is in the pool ?
  - Where do you ride a bicycle ?
  - Do the children eat the vegetables ?