Learn Hardcore Chinese: Tā juéde xuéxí hé gōngzuò de yālì yǒudiǎnr dà. - She feels the pressure from study and work is a bit heavy.

So it literally feels like:
She feels [study and work’s pressure] a bit big.
In natural English: She feels the pressure from studying and working is a bit too much.

Why do we use 觉得 (juéde) here? Can I replace it with 想 (xiǎng) or 认为 (rènwéi)?

觉得 is the most common everyday verb for subjective feelings or impressions:

我觉得今天有点儿冷。
I feel / think it’s a bit cold today.

You can sometimes replace it, but the nuance changes:

想 – more like to think / to want, often about plans or intentions.
- 她想学中文。 – She wants to learn Chinese.
  Using 她想学习和工作的压力有点儿大 is unnatural.
认为 – more formal, like to be of the opinion that, often used for more serious or objective statements.
- 专家认为这个方法很好。 – Experts are of the opinion that this method is good.

In this sentence, it’s about her personal feeling, so 觉得 is the most natural choice.

What does 的 (de) do in 学习和工作的压力? Why is it needed?

Here 的 links a modifier to a noun, forming something like “X’s Y” or “the Y related to X”.

学习和工作 – study and work
压力 – pressure
学习和工作的压力 – the pressure of study and work / the pressure from studying and working

Structure:
[modifier] + 的 + [noun]

Examples:

学习的时间 – the time for study
工作的地方 – the place of work
家里的事情 – things at home

Without 的, 学习和工作压力 is not wrong in all contexts, but 学习和工作的压力 sounds clearer and more natural for learners.

Why is it 学习和工作的压力 and not something like 压力学习和工作?

In Chinese, modifiers usually come before the noun they describe:

English: the pressure of study and work
Chinese order: study and work + 的 + pressure

So we say:

学习和工作的压力 – literally study and work’s pressure

Putting 压力 first (压力学习和工作) would be incorrect word order. The noun (压力) generally comes after what describes it.

What exactly does 有点儿 (yǒudiǎnr) mean here? Is it just a little?

有点儿 literally means “to have a bit”, but its feeling is very important:

It usually goes before adjectives: 有点儿 + Adj
It often carries a slightly negative / complaining tone: “a bit too…”

In this sentence:

有点儿大 – a bit too big / a bit too much (in a slightly negative way)

Comparisons:

有点儿贵 – a bit too expensive (complaint)
有点儿冷 – a bit too cold (not ideal)

So 她觉得学习和工作的压力有点儿大 suggests she feels the pressure is a bit too much for her, not just neutrally “a little big”.

How is 有点儿 different from 一点儿 (yìdiǎnr) or 有一点儿 (yǒu yìdiǎnr)?

They all involve “a little”, but usage and feeling differ:

有点儿 + Adjective
- Often negative / complaining
- 有点儿难 – a bit too difficult
- 有点儿大 – a bit too big, slightly too much
一点儿 + Noun
- Quantifying things, more neutral
- 一点儿水 – a little water
- 一点儿时间 – a little time
有一点儿 + Adjective
- Similar to 有点儿, but sounds a bit more neutral/gentle
- 有一点儿大 – a little bit big / slightly big
  In speech many people shorten it to 有点儿 anyway.

In this sentence, 有点儿大 is very natural and common.

Why is it 有点儿大 and not 大有点儿?

In Chinese, degree words like 很, 非常, 有点儿 usually go before the adjective they modify:

很大 – very big
非常忙 – extremely busy
有点儿贵 – a bit too expensive

So the normal pattern is:

有点儿 + Adjective

Putting 大有点儿 is incorrect word order. The degree word must come first: 有点儿大.

Why do we use 大 (dà) with 压力 (pressure)? Does it mean “big pressure”?

Yes, 大 literally means “big”, but with 压力, it means “strong / heavy / high” pressure.

This is a natural collocation:

压力很大 – the pressure is high / heavy
学习压力很大 – study pressure is huge

You wouldn’t normally say:

压力高 – understandable but not as natural as 压力大
压力重 – possible, but 压力大 is much more common.

So 压力有点儿大 means the pressure feels a bit too heavy/high.

Why is it 学习 (xuéxí) instead of just 学 (xué)?

Both 学 and 学习 mean to study / to learn, but:

学习 is slightly more formal or neutral and is very common as a noun-like activity word:
- 学习很忙。 – Studying is busy / There’s a lot to study.
- 学习压力 – study pressure
学 is shorter and often used as a verb with an object:
- 学中文 – learn Chinese
- 学开车 – learn to drive

Here, 学习 is grouped with 工作 as activities:

学习和工作 – studying and working

Using just 学和工作 would sound incomplete and less natural in this noun-like position.

Why do we use 和 (hé) between 学习 and 工作? Can I use 跟 (gēn) instead?

In this sentence, 和 simply means “and”, joining two similar items:

学习和工作 – study and work

和 is the most common neutral linking word for X and Y in a list.

跟 can also mean “and / with”, but:

It more often has the feel of “with (someone)”:
- 我跟他去。 – I go with him.
In lists like A and B, 和 is the safer, more standard choice in written and general speech.

So 学习和工作 is more natural than 学习跟工作 here.

Why is there no 是 (shì)? Why not 她觉得学习和工作的压力是有点儿大?

Chinese often does not use 是 between a noun and an adjective. We directly say:

压力大。 – The pressure is big.
天气冷。 – The weather is cold.

The basic pattern is:

Noun + Adjective

So here:

学习和工作的压力有点儿大
literally: study and work’s pressure a bit big

You can say:

她觉得学习和工作的压力是有点儿大的。

This version:

Adds 是 and 的, sounding more emphatic or explanatory, sometimes used in contrast or when stressing a point:
- 学习和工作的压力是有点儿大的，但是她还是坚持。
  The pressure from study and work is a bit much, but she still persists.

For a simple statement of feeling, the shorter original form is more natural.

What about the 儿 in 有点儿? Is it necessary? Can I just say 有点?

The 儿 (ér) here is an “erhua” sound, very common in northern Mandarin (especially Beijing).

有点儿 (yǒudiǎnr) – northern / standard textbook form
有点 (yǒudiǎn) – also common, especially in the south or in less “erhua” speech

Both are understood and accepted.

In writing: both forms appear, 有点儿 is very common in textbooks.
In speaking: you can follow the accent you’re learning; both are fine.

The meaning and grammar are the same.

Could I say 她觉得学习和工作的压力挺大 instead? What’s the difference?

Yes, you can say:

她觉得学习和工作的压力挺大。

挺…的 means “quite / pretty …”, often without a strong negative tone:

挺好 – quite good
挺累 – pretty tired

Differences in feeling:

有点儿大 – a bit too big, slightly complaining
挺大 – quite big, fairly strong; more neutral, can be just a description

So:

有点儿大 – she feels it’s a bit too much for her
挺大 – she feels the pressure is quite strong, but not necessarily complaining as clearly.