A Clause is a group of words that forms part of a sentence and has a subject and a finite verb of its own. In simple language we can say — a clause is a sentence within a sentence.
1. This is the man who won the trophy.
2. I know that it is true.
3. Tell me where you go.
4. My uncle is a man whom everybody respects.
In the above sentences there are two parts.
|Part 1||Part 2|
|1. This is the man||who won the trophy.|
|2. I know||that it is true.|
|3. Tell me||where you go.|
|4. My uncle is a man||whom everybody respects.|
Part 1 in these sentences does not depend on Part 2. But Part 2 depends upon Part 1 to give its complete sense. Part 1 is independent and therefore called as Independent or Main or Principal Clause. And Part 2 is called Subordinate or Dependent Clause.