Learn Hardcore Chinese: qǐng nǐ rènzhēn de kàn, ránhòu gàosu wǒ nǐ dǒng bù dǒng. - Please look carefully, then tell me whether you understand.

请 makes the imperative polite: “please…”. Omitting it (你认真地看…) is still a command but less polite. With peers, 请 can sound a bit formal or bossy; you can soften with 麻烦你… or 可以…吗.

Why is 你 (nǐ) used twice? Can I drop one of them?

It marks the subject for both actions: 你看 and 你…告诉我. In speech, the second 你 before 懂不懂 is often dropped because the subject is obvious: 请认真地看，然后告诉我懂不懂. The first 你 after 请 can also be omitted: 请认真地看….

Why 认真地 (rènzhēn de) with 地, not 的?

地 turns an adjective/adjectival phrase into an adverb modifying a verb: 认真地看 = “look carefully.” Rough rule of the three de:

的: before a noun (attributive), e.g., 认真的学生.
地: before a verb (adverbial), e.g., 认真地看.
得: after a verb/adjective (complement), e.g., 看得很认真.

Can I say 认真看 without 地?

Yes. 认真看 is very common and slightly more colloquial; 认真地看 is a bit more formal or careful in writing. Both are natural.

How do I pronounce 地 here?

As neutral-tone de (no tone), not fourth tone dì. It’s a grammatical particle in this use.

Does 看 (kàn) mean “look” or “read” here?

It can mean either, depending on context. With no object, it usually means “look (at it)/read it” from context. If you want to stress finishing reading, say 看完; to soften, 看一下/看一看.

Why use 然后 (ránhòu)? Can I use 再 (zài) instead?

Both are fine:

然后 states chronological order: do A, then B.
再 in imperatives suggests the next step: do A, then (after that) do B. In instructions, …先…，再… is very common: 请认真看，再告诉我….

What’s the difference between 告诉 (gàosu) and 说 (shuō), 跟/对 someone 说?

告诉 + 人 + 事情: “tell/inform” (more definite). Example: 告诉我结果.
跟/对 + 人 + 说: “say to (someone)” (neutral speaking). Example: 跟我说一下.
Bare 说 focuses on the act of speaking, not necessarily informing. In this sentence, 告诉我 is the most idiomatic.

How is 告诉 pronounced? I often hear people say it like “gàosù”.

It’s gàosu: the second syllable su has a neutral tone. Don’t pronounce it as gàosù (that’s the word 高速 gāosù, “high-speed”).

What is the A‑not‑A pattern in 你懂不懂?

It’s a yes–no question formed by repeating the verb/adjective with 不 between: 懂不懂 (“understand or not”). It’s very natural in speech. Alternatives:

你懂吗？
你是否懂？ (formal)
你懂了没有？/ 懂没懂？ (asks about completed understanding)

Should I use 懂 (dǒng), 明白 (míngbai), or 知道 (zhīdào)?

懂/明白: “understand” (very close; 明白 can sound a hair more explicit/clear).
知道: “know/be aware (of a fact)”. Here use 懂 or 明白: 你懂不懂/你明白不明白. Use 知道不知道 for factual knowledge.

Why not use 你懂了没有？ What’s the nuance vs 你懂不懂?

你懂不懂 asks generally whether you understand (state).
你懂了没有 focuses on whether a change to the “understood” state has happened (completion), often after an explanation. Both are fine; pick based on nuance.

Can I ask 你看得懂吗？ instead of 你懂不懂?

Yes, but it’s slightly different:

你看得懂吗？ asks if you can understand by looking/reading (ability/result complement 得).
你懂不懂？ asks whether you understand (in general, not tied to the act of looking). In this sentence, after 看, either can work depending on what you’re checking.

Any tone-sandhi tips for pronouncing 你懂不懂?

你 (nǐ) before 懂 (dǒng): third tone + third tone → pronounce as ní dǒng (2-3).
不 (bù) stays fourth tone here because it only changes to bú before a fourth tone (e.g., 不是 búshì). So: ní dǒng bù dǒng.
地 and the second syllable of 告诉 are neutral tones.

Is the comma required? Could I write it without punctuation?

A comma naturally separates the two clauses: …看，然后告诉…. In running text you could omit it, but standard writing uses the comma to mark the pause and sequence. Speech will also pause there.

Is 请你… always polite? Could it sound too direct?

It’s polite on the surface but can feel directive, especially with equals. To soften:

麻烦你认真看一下，然后告诉我…
可以请你认真看一下吗？然后告诉我…
Drop 请你 with friendly tone: 认真看一下，然后告诉我…