Help understanding this sentence “你不会不明白的”

Question

I saw this sentence when I was watching a TV play. I don't understand what it means. The heroine said this to the hero. My brother thinks this sentence means "you don't understand". However, I think this sentence means "you know". So we quarreled. I need you to help me understand what this sentence means.

I asked my friend. He told me that this is a Chinese rhetorical device called "double negation means affirmation". I don't understand this rhetorical device. I hope you can provide more such sentences.

Answer 1

你(You) 不会(won't) 不(not) 明白的(understand/know), so you are correct, it means "you know"

In Chinese, double negatives cancel one another and produce an affirmative, it usually carries an emphasis with it. For example:

• 我不得不离开这里 — I cannot not leave here — I must leave here
• 没有人不喜欢他 — No one doesn't like him — Everyone likes him

If you use multiple "double negation means affirmation" at the same time, you can create "triple negation means negation"

• 他不得不承认自己长得不好看 — He cannot not admits that he doesn't look good — He admits that he doesn't look good (不得不 is a double negation)

and even "quadruple negation means affirmation"

• 我不是不知道没有人不喜欢他 — I don't not know no one doesn't likes him — I know everyone likes him (不是不 is a double negation, 没人不 is another double negation)

Answer 2

你不会不明白的 implies that you would understand it (although it seems that you don't understand now). The speaker makes the judgement based on the knowledge about her/his friend. It's like saying 你(肯定)会明白的.

This kind of double negative is usually used when the speaker have the confidence that something is true. The double negative just adds an emphasis on the certainty. E.g.

A: 我不知道这件事。

B: 你不可能不知道。// meaning you must know it.

Answer 3

As a native speaker, for me the usage of "double negation means affirmation" is a kind of emphasis or refutation. For example:

• 不得不说，……->I have to say ...
• 你不会不明白的。->You won't fail to understand.

The implied meaning in “你不会不明白的” is not "You may understand", but "You must understand!". The use of "double negation means affirmation" squeezes out the last bit of sophistry.

Answer 4

You are correct. “你不会不明白的” means "You Know". (negative negative equals positive)

i.e.

妳煮的菜不會不好吃的！