The sentence:

My sister who is from Chicago visited me last weekend.

The interpretation from YouTube: I have more than one sisters and I am specifically talking about my sister who is from Chicago.

Question: If I say,

"The car that I bought last week is red"

Will people think that I have more than one cars? (Ooops, do I have to add s at the end of car in this sentence?

I am a nonnative speaker who enjoy learning English. Please help me with this interpretation.

  • If you said "my car that I bought last week ...", people might think you have more than one car. But if you say "the car that I bought last week ...", they won't. Jan 19, 2012 at 6:53
  • @Peter Shor: I wouldn't. Would you think me a bigamist if I said "You must meet my wife who I married last week"? (we'll assume you can't hear whether I intended any commas! :) Jan 19, 2012 at 14:28
  • @FumbleFingers: there is a difference in intonation between restrictive and non-restrictive clauses. But for wives, at least, that would be overridden by the context. Jan 19, 2012 at 15:05
  • possible duplicate of Is it appropriate to put a comma before "which"?
    – MetaEd
    Jan 19, 2012 at 15:27
  • We ought to try to save Barry from having to write the same description of the use of comma to set apart non-restrictive clauses, irrespective of whether the clause is introduced by "which" or "that". I suggest we pick one or the other of these as the best "Barry answer".
    – MetaEd
    Jan 19, 2012 at 15:29

5 Answers 5


There are two types of English relative clause. Their traditional names are defining (or restrictive) and non-defining (or non-restrictive). ‘The Cambridge Grammar of the English Language’ uses the terms integrated and supplementary, which seem to me to explain their difference more clearly. Integrated relative clauses are essential to the meaning of a sentence and cannot be omitted if the meaning is to be retained. Supplementary relative clauses provide additional information. When a supplementary relative clause is removed, a sentence with the same underlying meaning remains.

It is the convention to set off supplementary relative clauses with commas, so that if your first example had included a supplementary relative clause it would have appeared as ‘My sister, who is from Chicago, visited me last weekend.’ That would have left little doubt that you had only one sister. Without commas, the clause ‘who is from Chicago’ becomes an integrated relative clause and leaves the reader with the strong impression that you have more than one sister but that the one who visited you last week-end is from Chicago.

The sentence ‘The car that I bought last week is red’ contains the integrated clause ‘that I bought last week’. It tells us that of all the possible cars you could be talking about you are talking about only one, that is, the one you bought last week. The sentence about your aunt who is from Chicago doesn’t deny the possibility that there might be other aunts elsewhere. Similarly, the sentence about the car you bought last week doesn’t deny the possibility that there might be other cars elsewhere. You aren’t contrasting the car you bought with any other cars you may already own, but with all the other cars in the world. If we were to treat the clause as supplementary and write ‘The car, that I bought last week, is red’ we could remove the clause and be left with ‘The car is red’ and that would be a grammatical sentence. But it conveys different information, lacking as it does the crucial point about which particular car you’re talking about, that is, the one you bought last week.

  • @Kwanbhan: Hope it helps. Jan 26, 2012 at 18:52
  • Can you explain whether the following sentences (which I got from a novel) should have an integrated or a supplementary relative clause and why? :- (1) "After a length of time which he made no attempt to judge, he sensed a slight subsidence in their speed"; (2) "He turned toward his craft which, though no apparent signal had been given, now drifted quietly toward them through the dark"; (3) "From time to time a doorway led either to the left or right into smallish chambers which Ford discovered to be full of derelict computer equipment". Jan 22, 2020 at 18:44

The two sentences you presented aren't really related in any way.

The sentence "my sister who is from Chicago" doesn't necessarily mean that you have more than one sister, but since you define which sister exactly (the one from Chicago), it is expected that you have more of them, otherwise you wouldn't define which exactly.

To not define which exactly, yet still use the part, you'd surround it with commas, to make that part "secondary", like this:

My sister, who is from Chicago, the rest of the sentence.

As for the sentence with a car, it doesn't say anything about how many cars you already have. I think the explanation I provided above will help you resolve everything you need to know. If not, comment and I'll expand my answer to provide further information you may need.

  • "The sentence "my sister who is from Chicago" doesn't necessarily mean that you have more than one sister..." -- can you elaborate on why this doesn't necessarily mean that you have more than one sister? Jan 22, 2020 at 18:28

For an interpretation of the sentence with the car, if it is parallel to the first sentence, you could read it as the car is red, with an added specifier of that I bought, which could imply that I own many cars, but only one that I bought. Typically though, the car that I bought implies only that there are many cars, but only one that I bought.


I'd say the YouTube interpretation is wrong. When you say "My sister who is from Chicago ... ", this does NOT imply that you have more than one sister.


Relative clauses defining \ non-defining I would explain all the lesson and you get me word after word

Your examples : and before I discuss your examples. Don't you ask yourselves " why or for what reason we use the defining or the non-defining? if both are the same or give the same result, we use either one of these to all examples I see you think that there is no difference. No, surely there is difference as well as difference in meaning. We use the defining relative clause ( no comma ) when there is many supposed things, so we define the one we are talking about. Examples : The village where I grew up is very old. defining Suppose it non-defining ( using commas ) The village, where I grew up, is very old. Remove the extra information : The village is very old. = any village can be very old = not clear which village we tell about though is modified by ( the) Ask this question : Which village is very old = the village where I grew up there. Now in the defining becomes clear The main function of the relative pronoun is to define the noun.

If it does not define the noun = necessary Otherwise, what's its function then ?

your examples you are likely disputed about

"The car that I bought last week is red. Object ( optional) you can omit ( that ) The car I bought last week is red. is white \ is green one car whatsoever its color is changed 2 clause 2 : My sister who is from Chicago visited me last weekend.

defining = he has more than sister and this one ( particular) who is from Chicago visited him last week .. Perhaps other sisters do not live in Chicago Again why do we define this one ( sister ) ? Answer : We define her to turn the speech is specific to her. We define her to put her in a position is known to the listener or reader. If we say : My sister Layla, who is from Chicago, visited me last weekend In this case ( last example ) The sister is defined by a name and when a subject is defined by a name = is known to others and here does not need to define

I am a master in English and more than forty years I have been a teacher. Yes I am from Iraq, but got my master in English from the United State. For more information to you all or just to the asker visit these pages I recommend : Both pages are about the same idea Commas make different meaning https://www.ego4u.com/en/cram-up/grammar/relative-clauses/exercises?04


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