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
https://www.ego4u.com/en/cram-up/writing/comma?13