Clause

Clause is a part of a sentence which contains a subject and a verb, usually joined to the rest of the sentence by a conjunction.

e.g:

• Suzy said that she was happy.

The word clause is also sometimes used for grammatical structures containing participles or infinitives (no subject or conjunction). e.g.

• Not knowing where to go, I called Robert; I told him to try a different path.

FORMULA: Phrase < Clause < Sentence

Main Clause is Some sentences consist of a main clause and one or more subordinate clauses. A subordinate clause acts like a port of the main clause (like a subject, an object, or an adverbial). 

e.g.

• Who you are doesn’t matter.

                 S

• I told him that I didn’t care.

                                d.o.

• Where you go, you’ll find Coca-cola.

                 adv.

Co-ordinate Clause is one, two, or more clauses of equal “value” that make up a sentence. It doesn’t function as a subject, object, complement or adverbial.

e.g:

• It’s hot today and there’s a lot of sun.

Subordinate Clause is a clause which functions as part of another clause (as subject, object, or adverbial)

e.g:

• What I need is a sandwich. (subject)
• I thought that he crashed. (object)
• I’ll dream of you wherever you are. (adverbial)

Relative Clauses is clauses, beginning with relative pronouns who, which, where…, used to identify people or things, are called relative clauses.

e.g:

• There’s a program on T.V. which you might like.

Relative when and where introduce clauses referring to time and place. Why is used after reason.

e.g:

• I’ll never forget the day when I first met you.
• Do you know a shop where I find shoes?
• Do you know the reason why she doesn’t like me?

Object pronouns can be left out.

e.g:

• She’s somebody I can’t stand. (..somebody that…)

Relative pronouns have a double use. As subjects or objects, they can replace words like he or him.

• She’s got a boy-friend. He studies English.
• She’s got a boy-friend who studies English.

Whose is a possessive relative word. It replaces his, her or its. e.g.

• I saw a girl whose hair is blond. (Not…whose her hair…)

Which can refer to a noun or to a clause. What, that and how cannot be used in the same way. e.g.

• He got married, which surprised me. (Not…, what/that surprised…)

That

That can refer to things, and in an informal style to people. 

e.g:

• Where is the girl that sells the tickets?
• Where is the girl who sells the tickets?

           who and whom

In an informal style, who can be used as an object. Whom is more formal.

 e.g:

• The woman who I marry has a sense of humor.
• The woman whom I marry has a sense of humor.

       Omission of a subject

In informal style, after there is.

e.g:

• There’s a man at the door wants to talk to you