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Defining and non-defining clauses...

Posted: Tue Jun 27, 2006 12:53 am
by pambele
Can anyone explain the difference in layman's terms?


Defining and Non-Defining Classes

Posted: Tue Jun 27, 2006 6:31 pm
by nikita

In simple words about the defining and non-defining classes.

If you remove a non-defining clause (a kind of a smaller sentence that is a part of a bigger sentence), some information will be definitely lost, but it will still remain a normal and meaningful English sentence. This is because the clause does not define anything; it just provides some more information.

If you remove a defining clause from a sentence, the meaning will inevitably be lost.

Here are a few examples from Headway. You can easily see whether a noun is already clearly defined or not. If it is clearly defined, then we will most likely have a non-defining relative clause after it. Otherwise, the noun should be followed by a defining relative clause.

People _____ live longer. (Defining Relative Clause – what people?)

She married a man ____ (Defining Relative Clause – what man?)

Let me introduce you to Peter James (Non-defining. I don’t suppose you know many guys called Peter James.)

My great aunt Freda ____ is coming to lunch. (Non-defining. I have only one great aunt called Freda.)

And the full sentences from Headway.

People who do regular exercises live longer.

She married a man that she met on holiday in Turkey.

Let me introduce to Peter James, who works in our Paris office.

My great aunt Freda, who I was telling you about last night, is coming to lunch.

Any further questions are welcome.

By the way, there was once a discussion on defining & non-defining relative clauses at
You may find some stuff discussed there useful.



Re: Defining and Non-Defining Classes

Posted: Thu Jun 29, 2006 10:30 pm
by nikita
Hello again

What you also need to remember is that non-defining clauses are separated by commas, while defining clauses are not.

And here is another very good example from Headway.

I had a cocktail that was very unusual.
I had a cocktail which was very unusual.

These two sentences have absolutely identical meanings.

I had a cocktail, which was very unusual.

In this sentence you have a non-defining relative clause, because there is a comma (,) followed by “which”. This sentence means that it was very unusual for me to have a cocktail. (Because normally I don’t touch alcohol or something like this.) By the way, only “which” in a non-defining relative clause can refer to the whole preceding sentence.

I had a cocktail, that was very unusual.

This sentence is obviously wrong, because you can never put “that” into a non-defining relative clause.

Give me a shout if you have any other questions.


Posted: Mon Jul 17, 2006 10:00 pm
by pambele
Thanks very much, Nikita. I kind of cracked it before I read your excellent posts, which just confirms things. Essentially, anything parenthetical requires commas and non-defining clauses are parenthetical remarks in a bigger clause.
Again, thank you.