A defining relative clause (also known as a restrictive relative clause) provides essential information about the noun or noun phrase it modifies, the purpose of which is to define that noun or noun phrase. The clause cannot be removed without changing the meaning of the sentence.
When ‘that’ is used as the object in a defining relative clause, it refers to a noun mentioned earlier in the sentence and introduces additional information about that noun. Here’s an example:
“The book that you recommended is fantastic.”
In this sentence, ‘that’ is used as the object of the relative clause and refers back to ‘the book’. The relative clause ‘that you recommended’ provides essential information about ‘the book’. If we remove this clause, the sentence “The book is fantastic” is too general and the meaning changes.
It’s important to note that when ‘that’ is the object of the verb in the relative clause, it can often be omitted:
“The book you recommended is fantastic.”
Research Notes
At the A2 level, learners can use “that” to refer to things such as a singular group or “team” of people, whereas at B1 “that” can be used to refer to the humans: “people, actors, friends or a girl”. That is what these two points on the English Grammar Profile seem to suggest. The explanations do not offer any difference for being able to use “that”. As a result, this is another post about trying to understand from the examples given, what the difference in the criterion is. Obviously “who” is the main difference, but when we are trying to classify the level of “that” it does not make much difference. I would suggest that “to refer to people” should be added to the B1 explanation.
DEFINING, OBJECT, WITH ‘THAT’ in CLAUSES (point 33) relative A2: defining relative clause with ‘that’ as the object.
The team that I like is called ‘The Monkeys’, but Paty prefers ‘The Walls’.
I bought some clothes that I will need for my trip to Greece.
Please, wear clothes that you can get dirty; use old clothes, okay?DEFINING, OBJECT, WITH ‘WHO/THAT‘ in CLAUSES (point 65) relative B1: defining relative clause with ‘who’ or ‘that’ as the object.
My friends are the people who I love most.
They filmed two actors who I don’t really know arguing and kissing after it.
It was Sarah, a girl who I met in Spain on my holiday last year.
We are going with my friends Paolo and Ontorio, the guys who you met yesterday.
So I sent a letter to the school and they have sent me the details of the people that I’m going to stay with.
All the examples above use a pronoun after the relative pronoun, which doesn’t tell us much about variation, so below is an iWeb Corpus search for the 50 most frequent Ngrams of:
_nn* that_cst _nn* _v*
We soon realise that they do not all meet the criteria for defining object pronoun usage. We see high-level common phrases that focus much of our attention at the start of sentences. In bold then, are some of the possible ones we may want to investigate more. Without manual checking of every Ngram in context, this list as it stands does not offer much information on the exact grammar structure in the title!
1 THING THAT MATTERS IS 1747 (claws 7 tagger can’t differentiate between plural nouns and third-person singular present simple)
2 FACT THAT PEOPLE ARE 1732
3 THINGS THAT PEOPLE DO 864
Now you‘re just listing things that people do.
4 FACT THAT WOMEN ARE 545
5 THINGS THAT PEOPLE ARE 520
6 THINGS THAT PEOPLE HAVE 472
7 WAYS THAT PEOPLE CAN 464
8 THINGS THAT PEOPLE CAN 443
9 WAY THAT PEOPLE CAN 443
10 FACT THAT PEOPLE HAVE 435
11 IDEA THAT PEOPLE ARE 427
12 THING THAT CHANGES IS 408
13 FACT THAT PEOPLE DO 389
14 WAY THAT PEOPLE ARE 347
15 THING THAT PEOPLE DO 329
16 MISTAKES THAT PEOPLE MAKE 325
17 FACT THAT PEOPLE CAN 322
18 IDEA THAT WOMEN ARE 299
19 THING THAT WORKS IS 292
20 MISTAKE THAT PEOPLE MAKE 287
21 SIGN THAT THINGS ARE 284
22 FACT THAT PEOPLE WERE 266
23 SKILLS THAT EMPLOYERS ARE 251
24 THING THAT PEOPLE ARE 248
25 THINGS THAT OTHERS DO 240
26 THINGS THAT PEOPLE WANT 236
27 IDEA THAT PEOPLE CAN 235
28 QUESTIONS THAT PEOPLE HAVE 215
29 FACT THAT PEOPLE WILL 212
30 FACT THAT LIFE IS 205
31 THINGS THAT PEOPLE SAY 205
32 STUFF THAT DREAMS ARE 204
33 PROBLEMS THAT PEOPLE HAVE 202
34 FACT THAT MEN ARE 195
35 FACT THAT HUMANS ARE 192
36 QUESTIONS THAT PEOPLE ASK 192
37 THINGS THAT PEOPLE WILL 191
38 REASON THAT PEOPLE ARE 186
39 FACT THAT THINGS ARE 183
40 WAYS THAT PEOPLE ARE 181
41 HOPE THAT PEOPLE WILL 180
42 EVIDENCE THAT PEOPLE ARE 177
43 FACT THAT WOMEN HAVE 177
44 IDEA THAT PEOPLE SHOULD 176
45 FACT THAT CHILDREN ARE 175
46 SENSE THAT PEOPLE ARE 174
47 IDEA THAT HUMANS ARE 169
48 SKILLS THAT STUDENTS NEED 168
49 WAY THAT PEOPLE WILL 168
50 FACT THAT TRUMP IS 167
In the following Ngram:
_nn* who_pnqs _p* _v*
on iWeb corpus, we see that preceding “who + pronoun” the main nouns used for our criteria are “people, person, man, friends, friend and guy.” There is no claim here that these meet the “object criteria”. On the whole, one could make a general claim “that” with things is more common than “who” with people, and start to draw a relationship to the level of English related to such. What is rarer is usually found at higher levels of proficiency.
2 PEOPLE WHO YOU ARE 446
5 PEOPLE WHO I HAVE 369
6 PEOPLE WHO YOU CAN 368
7 PEOPLE WHO I KNOW 341
9 PEOPLE WHO YOU KNOW 287
12 PEOPLE WHO YOU THINK 241
13 PEOPLE WHO YOU DO 230
15 PEOPLE WHO YOU WANT 206
17 PEOPLE WHO I ‘VE 199
18 PEOPLE WHO YOU HAVE 186
21 PERSON WHO YOU ARE 182
22 PEOPLE WHO I THINK 180
23 PEOPLE WHO I DO 166
24 PEOPLE WHO WE ARE 166
25 PEOPLE WHO I WOULD 164
26 MAN WHO THEY SAY 163 (not object)
27 PEOPLE WHO THEY ARE 161
28 PEOPLE WHO I AM 152
29 PEOPLE WHO I THOUGHT 148
30 PEOPLE WHO I CAN 148
31 PEOPLE WHO YOU WOULD 146
36 PEOPLE WHO I WAS 105
37 PEOPLE WHO I KNEW 103
38 PEOPLE WHO THEY THINK 103
39 PERSON WHO YOU CAN 102
40 PERSON WHO I AM 96
41 FRIENDS WHO I HAVE 95
42 PEOPLE WHO WE HAVE 94
43 FRIEND WHO I HAVE 93
44 GUY WHO I THINK 92 (not object)
46 PERSON WHO THEY ARE 89
*Note removal of lines of nouns unrelated to “people”