zhèxiē shēngcí bù duō, dànshì yòng zài jùzi lǐ bú tài róngyì.

Yes. 这些 means these.

• 这 = this
• 些 = a plural marker meaning some / these
• 这些生词 = these new words / these vocabulary words

A useful point: 些 already makes the noun phrase plural-ish, so you do not add a measure word here. That is why it is 这些生词, not something like 这几个生词 unless you specifically want to say these few words.

生词 means new words, unfamiliar words, or vocabulary words you have not learned yet.

• 生 here has the idea of unfamiliar / not yet known
• 词 means word / term

So in language-learning contexts, 生词 is a very common word for vocabulary that is new to the learner.

不多 literally means not many.

So:

• 这些生词不多 = There aren’t many of these new words

This is a very natural way in Chinese to say that the quantity is not large.

Compared with other options:

• 很多 = very many / a lot
• 很少 = very few

不多 is often a bit softer and more neutral than 很少. It simply says the amount is not large, without strongly emphasizing scarcity.

Because 但是 means but, and it connects two contrasting parts:

• 这些生词不多
• 但是用在句子里不太容易

So the sentence structure is:

• statement 1: There aren’t many new words
• contrast: but
• statement 2: using them in sentences is not very easy

In written Chinese, a comma before 但是 is very common when joining two clauses like this.

Great question. The sentence is using a very common Chinese pattern where the topic is stated first, and then the comment about it comes afterward.

The topic is:

• 这些生词

Then the comment is:

• 不多，但是用在句子里不太容易

So the second part really means:

• These new words are not very easy to use in sentences

Chinese often leaves out repeated words when they are already understood. In natural English, we need to say them or repeat these new words, but Chinese can simply omit it.

用在 means to use in or more literally to use [something] in/on.

Break it down:

• 用 = use
• 在 = in / at / on
• 句子里 = in sentences

So:

• 用在句子里 = used in sentences / to use in sentences

In this sentence, it describes the new words:

• 这些生词……用在句子里不太容易
• These new words … are not very easy to use in sentences

This is a compressed Chinese way of speaking. In fuller Chinese, you could also say something like:

• 这些生词放在句子里不太容易用
• 这些生词在句子里不太容易用

But the original sentence is natural and concise.

Yes, both are possible, but they feel slightly different in structure.

• 用在句子里 focuses on being used in sentences
• 在句子里用 focuses first on the location/context in sentences, then the action use

In many cases, both are understandable and natural. The original version sounds compact and smooth, especially in written or careful spoken Chinese.

So:

• 这些生词用在句子里不太容易
• 这些生词在句子里用不太容易

The first one is generally the cleaner version here.

This is a pronunciation rule called tone sandhi.

Normally, 不 is fourth tone: bù.

But when 不 comes before another fourth-tone syllable, it changes to second tone: bú.

So:

• 不多: 多 duō is first tone, so it stays bù duō
• 不太: 太 tài is fourth tone, so it changes to bú tài

This change is about pronunciation, not meaning.

In this sentence, 不太容易 usually means not very easy or rather difficult.

Even though 太 can sometimes mean too, in the pattern 不太 + adjective, it usually softens the statement:

• 不太好 = not very good
• 不太清楚 = not very clear
• 不太容易 = not very easy

So here it does not mean not too easy in the English logical sense. It means something closer to:

• It’s somewhat difficult
• It’s not all that easy

里 means inside / in.

So:

• 句子 = sentence
• 句子里 = in the sentence / in sentences

Here it means within sentences, that is, in actual sentence use.

Chinese often adds 里 after a noun to show location or scope:

• 房间里 = in the room
• 书里 = in the book
• 句子里 = in the sentence / in sentences

You may also see 句子中, which is a bit more formal. 句子里 is very common and natural.

Because Chinese often omits objects when they are obvious from context.

The topic 这些生词 has already been introduced, so after that, Chinese does not need to repeat it. The listener already knows what is being used.

So the logic is:

• As for these new words, there aren’t many, but [they] are not very easy to use in sentences.

This kind of omission is extremely common in Chinese and is one reason Chinese sentences can feel more compact than English ones.