zhè gè wèntí wǒ yìdiǎnr yě bù dǒng.

Chinese often puts the topic first. In 这个问题我一点儿也不懂, 这个问题 means this question / this issue, and it is the thing being talked about first.

A very literal breakdown is:

• 这个问题 = as for this question / this issue
• 我 = I
• 一点儿也不懂 = do not understand at all

So the sentence is a topic-comment structure:

• Topic: 这个问题
• Comment: 我一点儿也不懂

You could also say 我一点儿也不懂这个问题, which is also natural, but the original version puts extra focus on this particular question/issue.

个 is a measure word (also called a classifier). In Chinese, when you use words like 这 (this) or 那 (that) before a noun, you usually need a measure word in between.

So:

• 这 = this
• 个 = general measure word
• 问题 = question / problem / issue

Together: 这个问题 = this question / this problem

For 问题, 个 is very common and natural.

This is a very common emphatic pattern:

• 一点儿也不 + verb/adjective

It means:

• not at all
• not even a little bit

So:

• 一点儿 = a little bit
• 也 = also / even
• 不懂 = don’t understand

Together, 一点儿也不懂 means don’t understand at all.

You should learn this as a fixed pattern. Similar examples:

• 我一点儿也不累。 = I’m not tired at all.
• 他一点儿也不高兴。 = He’s not happy at all.

懂 means to understand, especially in the sense of grasping or comprehending something.

In this sentence, 不懂 means don’t understand or don’t get.

It is often used for understanding:

• knowledge
• ideas
• explanations
• a subject
• how something works

Examples:

• 我不懂中文。 = I don’t understand Chinese.
• 你听懂了吗？ = Did you understand what you heard?
• 这个道理我懂。 = I understand this principle.

This is a very common learner question.

• 不知道 = to not know a fact, piece of information, or answer
• 不懂 = to not understand something

So:

• 我不知道答案。 = I don’t know the answer.
• 我不懂这个问题。 = I don’t understand this question/issue.

In your sentence, 不懂 is used because the speaker is saying they cannot understand the question/problem, not just that they lack information about it.

Yes. 问题 is a very flexible word and often means:

• question
• problem
• issue

The exact meaning depends on context.

For example:

• 我有一个问题。 = I have a question.
• 这个问题很严重。 = This problem is serious.
• 环境问题 = environmental issues/problems

So in your sentence, 这个问题 could mean:

• this question if someone asked something
• this issue/problem if the speaker means a topic they do not understand

Both are possible, but they are different in strength.

• 我不懂这个问题。 = I don’t understand this question.
• 这个问题我一点儿也不懂。 = I don’t understand this question at all.

Adding 一点儿也 makes the sentence much stronger and more emphatic. It tells the listener the speaker understands none of it.

Yes, very often.

• 一点儿也不懂
• 一点也不懂

Both are common in speech. The 儿 is associated especially with northern pronunciation and standard Mandarin forms. In many situations, learners will hear both.

A rough guide:

• 一点儿 is the fuller form
• 一点 is a very common shortened form in everyday speech

Both mean a little bit, and in this pattern both give the same overall meaning: not at all.

Yes. Tone changes happen here.

The dictionary forms are:

• 一 = first tone
• 点 = third tone
• 儿 = neutral / light in this word

But in normal speech, 一 changes tone depending on what follows.

Because 点 is a third-tone syllable, 一 is usually pronounced as fourth tone here:

• 一点儿 → yìdiǎnr

So the pinyin given is correct: yìdiǎnr.

Also, 儿 is often pronounced as a light ending attached to 点, so it sounds like diǎnr rather than a fully separate syllable.

Yes, 不 changes tone before a fourth-tone syllable.

• Normally: 不 = bù
• Before a fourth-tone syllable: bú

For example:

• 不是 = bú shì
• 不要 = bú yào

But here the next syllable is 懂 (dǒng, third tone), not fourth tone, so 不 stays bù:

• 不懂 = bù dǒng

Yes. 完全不懂 means completely don’t understand. That is natural too.

Compare:

• 这个问题我不懂。 = I don’t understand this question.
• 这个问题我一点儿也不懂。 = I don’t understand this question at all.
• 这个问题我完全不懂。 = I completely don’t understand this question.

All are natural, but 一点儿也不懂 is a very common everyday pattern.

Both are natural, but they emphasize slightly different things.

• 这个问题我一点儿也不懂。
  Emphasizes this question/issue. It sounds like As for this question, I don’t understand it at all.

• 我一点儿也不懂这个问题。
  Starts with I, so it feels more like a straightforward statement about the speaker.

Chinese often uses the first version when introducing a topic and then commenting on it.

Good question. 也 usually means also, but in negative emphatic patterns it can feel more like even.

In 一点儿也不懂, the idea is:

• not even a little

So while 也 by itself does not literally mean at all, the whole pattern 一点儿也不... is naturally translated as not at all.

This is why it is better to understand the whole chunk as one expression, rather than translating each word too literally.

It is neutral and very natural in everyday Mandarin. It works in:

• conversation
• class discussion
• written informal Chinese
• many ordinary spoken situations

If you wanted to sound more formal or polite, you might say:

• 这个问题我不太懂。 = I don’t quite understand this issue.
• 这个问题我不是很懂。 = I don’t understand this very well.

Those are softer than 一点儿也不懂, which is stronger and more absolute.