Learn Hardcore Chinese: Zhè gè xiǎozǔ de gōngzuò shì tā fùzé de, biéren bāng tā fùxí jīntiān de zhòngdiǎn. - He is in charge of this group’s work, and others help him review today’s key points.

小组的工作
- Structure: 小组 + 的 + 工作
- Function: possessive / attributive
- Meaning: the work of the group / the group’s work
  Here 的 links a noun (小组) to another noun (工作) to show “X’s Y” or “Y of X”.
今天的重点
- Structure: 今天 + 的 + 重点
- Function: also attributive
- Meaning: today’s key points
  Here 的 links a time word (今天) to a noun (重点) in the same way: “today’s key points”.
是他负责的
- Structure: 他负责 + 的
- Function: turns a verb phrase into something that describes a noun
- Literally: “(the work) that he is in charge of”
  Here 的 nominalizes/relativizes the verb phrase 他负责, so that the whole chunk 他负责的 can describe 工作:
这个小组的工作是他负责的
This group’s work is (the work) that he is in charge of.

So:

In 小组的工作 / 今天的重点, 的 links a modifier (小组, 今天) to a noun.
In 他负责的, 的 links a whole clause (他负责) to the noun it describes (工作, understood from context).

Why do we need 个 in 这个小组? Can we say just 这小组?

Chinese usually needs a measure word (classifier) between a demonstrative (这, 那) and a noun:

这 + 个
- 小组 = this group
那 + 个
- 小组 = that group

个 is the default, very common measure word, and it works fine with 小组.

Can you say 这小组?

In very casual spoken Chinese, people sometimes drop the measure word, especially with short, common nouns.
However, for learners and in standard written Chinese, 这个小组 is strongly preferred and sounds more natural.

So you should treat 这个小组 as the normal, correct form.

What exactly is the structure 是他负责的 doing? Why use 是…的 here, and can we omit 是 or 的?

是…的 is a common structure used to emphasize or clarify some part of a situation.

In this sentence:

这个小组的工作 是他负责的

the pattern is:

是 + [focus / emphasized part] + 的

Here the emphasized part is 他负责 (“he is in charge”), so the sentence is highlighting:

It is he who is in charge of this group’s work (not someone else).

About omitting parts:

Without 是…的:
- 这个小组的工作他负责。
  This is also correct. It just states the fact more neutrally: “He is in charge of this group’s work” (no special emphasis).
Can we drop 是 but keep 的?
- 这个小组的工作他负责的。
  This is possible in spoken Chinese, but sounds a bit informal or incomplete. 是 makes the structure clearer.
Can we drop the final 的?
- 这个小组的工作是他负责。
  This is not natural. With 是 focusing on a verb phrase like this, you normally need the final 的 to complete the structure.

So in standard, clear Chinese, 是他负责的 is the best form here. It:

identifies who is responsible
and adds a feeling of “this is an established fact / setup” and a bit of emphasis on 他.

Is 他负责的 like “he is responsible” (a complete sentence), or is it only part of the sentence?

他负责 by itself is a complete sentence:

他负责。 = “He is responsible / He’ll take care of it.”

But 他负责的 (with 的) is not normally a complete sentence. With 的, it becomes:

a descriptive phrase: “the one that he is in charge of” / “(the work) that he is responsible for”.

Examples:

这是他负责的。
This is the thing he is responsible for.
这个小组的工作是他负责的。
The work of this group is (the work) that he is responsible for.

So:

他负责 → predicate/verb phrase (“he is responsible”).
他负责的 → modifier/relative clause (“the thing that he is responsible for”).

Why is there a comma (，) instead of a period between the two parts of the sentence? Could they be two separate sentences?

The sentence is:

这个小组的工作是他负责的，别人帮他复习今天的重点。

In Chinese, commas are often used to connect two closely related clauses that in English might be written as two separate sentences or connected with “and”:

Clause 1: 这个小组的工作是他负责的。
Clause 2: 别人帮他复习今天的重点。

They could be written as two separate sentences with a full stop (。), and it would still be correct. Using a comma simply emphasizes that:

these two actions describe the same situation, and
they are tightly connected pieces of information about “him”.

So both:

…是他负责的，别人帮他复习今天的重点。
…是他负责的。别人帮他复习今天的重点。

are grammatically OK. The first feels more like a single, flowing description.

In 别人帮他复习今天的重点, how is the word order working? Why is 他 in the middle like that?

The structure is:

别人 – subject: other people
帮 – verb 1: help
他 – indirect object: him
复习 – verb 2: review
今天的重点 – direct object: today’s key points

So the pattern is:

Subject + 帮 + [person (indirect object)] + [verb] + [thing (direct object)]

Very similar to English “help him review today’s key points”.

Other natural variants:

别人帮他复习一下今天的重点。 (add 一下 to soften the action)
别人帮他把今天的重点复习一下。 (using 把 to highlight “today’s key points” as what gets reviewed)

But these word orders are not natural:

✗ 别人帮复习他今天的重点。
✗ 别人帮他今天的重点复习。(awkward)

So keep 他 right after 帮, and put 今天的重点 after 复习.

What is the difference between 帮 and 帮助? Could we say 别人帮助他复习今天的重点 instead?

Both 帮 and 帮助 mean “to help”.

帮:
- More colloquial and short.
- Very common in everyday speech.
- Often followed directly by the person and what you help them do:
  - 帮他复习
  - 帮我买东西
帮助:
- Slightly more formal.
- Can be used as a verb or a noun.
- As a verb, you can say:
  - 帮助他复习今天的重点。

So:

别人帮他复习今天的重点。 – very natural, conversational.
别人帮助他复习今天的重点。 – also correct, just a bit more formal or written-style.

In this context, 帮 is the most natural choice, but 帮助 is grammatically fine.

Could we use 给 instead of 帮 here, like 别人给他复习今天的重点?

Normally, no. 给 doesn’t replace 帮 in this structure.

帮 means “to help (someone) do something”.
给 mainly means “to give” or “for / to (someone)” as a preposition.

Sentences like:

✗ 别人给他复习今天的重点。

sound unnatural, because 给 by itself doesn’t carry the meaning of “help”.

You could say:

别人给他讲今天的重点。 – Other people explain today’s key points to him.

But for “help him review”, you should use:

别人帮他复习今天的重点。
or 别人帮他把今天的重点复习一下。

Why do we need 的 in 今天的重点? Could we say 复习今天重点 without 的?

今天的重点 is:

今天 + 的 + 重点
literally “today’s key points”.

The 的 here marks attribution/possession (“X’s Y”), very much like English ’s:

今天的重点 = today’s key points
今天的课 = today’s class
昨天的作业 = yesterday’s homework

Can we drop 的?

复习今天重点 is not natural in standard Mandarin.
With some time words and very short nouns, 的 can sometimes be dropped in fixed patterns, but 今天重点 is not a common phrase.

So you should keep 的 and say:

复习今天的重点。

What exactly does 重点 mean here? Is it “main point” or “important point(s)”?

重点 (zhòngdiǎn) literally means “heavy/important point”, and can be understood as:

key point(s)
main point(s)
focus / emphasis

In this sentence, 今天的重点 means:

the key points (of today’s lesson / today’s material)

Some examples:

这篇文章的重点是什么？
What are the main points of this article?
你要抓住学习的重点。
You need to grasp the key points of your study.

So here 重点 is a noun, referring to the important items or ideas that need to be reviewed.

Why is 他 repeated? Could we say …是他负责的，别人帮复习今天的重点 without the second 他?

The sentence uses 他 twice:

这个小组的工作是他负责的，别人帮他复习今天的重点。

First 他: subject of 负责 (“he is in charge”).
Second 他: indirect object of 帮 (“help him”).

Can we omit the second 他?

别人帮复习今天的重点。 – Grammatically possible but sounds unnatural and unclear.
Listeners will probably still understand, but it feels like something is missing.

Chinese often repeats pronouns in each clause, especially when their role changes (subject → object, etc.), to keep things clear and smooth.

So the natural form here is to keep both:

是他负责的，别人帮他复习今天的重点。

Does 别人 mean specifically “other people (not including me)”, “other people (not including him)”, or just “people in general”?

别人 (biéren) literally means “other person/people”, and it is context-dependent:

It usually means “other people” not including the main person just mentioned.
In this sentence, the main person is 他, so 别人 most naturally means:
- people other than him (and usually also not the speaker).

So here, a good interpretation is:

“Other people (not him) help him review today’s key points.”

Depending on context, 别人 can be:

other people in general – a vague group
others in some specific group – “the rest of the group”, “the other team members”, etc.

But it almost always excludes the main referenced person (here, 他).