Learn Hardcore Chinese: tā zhǎo bú dào zìjǐ de qiánbāo le, hěn bù gāoxìng. - He couldn’t find his wallet and was very unhappy.

很 is an adverb that often means “very”, but it can also act as a neutral linker between a subject and an adjective (especially with positive adjectives like 高兴, 忙, 累, etc.).
With 不高兴, which is already negative, adding 很 typically does add real emphasis, not just neutral linking.
So:
- 他不高兴。 – He is (just) not happy.
- 他很不高兴。 – He is very unhappy / quite upset.

Here, the context (he can’t find his wallet) matches the stronger feeling, so 很不高兴 fits well.

What exactly does 了 do in 他找不到自己的钱包了? Is it past tense?

了 in this position (at the end of the clause) is not a simple past tense marker. It usually indicates a change of situation or a new state.

In 他找不到自己的钱包了:

It implies: “Now, as things stand, he can’t find his wallet (any more / anymore).”
There is a feeling of “this is the current new situation”, often after some process (e.g. he has been looking and now has discovered he can’t find it).

Compare:

他找不到自己的钱包。 – He can’t find his wallet. (a plain statement; could be theoretical or general)
他找不到自己的钱包了。 – He (has ended up in a situation where he) can’t find his wallet now. (change / result)

So 了 here is a sentence-final 了 indicating a new state, not a straightforward past tense marker.

Why is 不 pronounced bú instead of bù in 找不到?

This is due to tone sandhi (tone change rules) in Mandarin.

The basic tone of 不 is 4th tone: bù.
BUT when 不 is followed by another 4th-tone syllable, it changes to 2nd tone: bú.

In 找不到 (zhǎo bú dào):

到 is 4th tone (dào)
So 不 changes from bù to bú → 找不到 is pronounced zhǎo bú dào.

This is a regular, automatic pronunciation rule and doesn’t change the meaning.

Why do we say 找不到 and not 不找到?

找不到 is an example of a potential complement structure:

Pattern: Verb + 得 / 不 + Resultative complement
找 = to look for
到 = a resultative complement meaning “to successfully reach / achieve / find”
找得到 = can find (able to find)
找不到 = cannot find (unable to find)

So 找不到 literally means “look-for-not-reach (the result of finding)”, i.e. “can’t find.”

不找到 is not idiomatic in this sense; it would sound like you are simply negating “to find” as a basic verb, but 到 is not a standalone verb here; it is a complement marking the successful result of 找. The grammar requires 找 + 不 + 到, not 不 + 找到.

What is the difference between 找不到 and just 找? Doesn’t 找 already mean “to find”?

找 by itself means “to look for / to search for.”

When you add the resultative complement 到, you shift focus to whether the action succeeds:

找 – to look for (the action of searching)
找到 – to find (to have successfully located something)
找不到 – to be unable to find (cannot successfully locate)

So in the sentence:

他找不到自己的钱包了 – specifically tells us about the failed result: he cannot find his wallet (even though he has presumably been looking).

Why is 的 needed in 自己的钱包? Can you omit it and say 自己钱包?

Here 的 is the possessive marker, similar to English “’s” or “of”.

自己 = oneself
钱包 = wallet
自己的钱包 = one’s own wallet

In modern standard Mandarin, 的 is normally required between a pronoun/noun and another full noun to show possession:

我的钱包 – my wallet
他的手机 – his phone
他们的房子 – their house
自己的钱包 – one’s own wallet

Omitting 的 (自己钱包) is not natural in this case. There are some set-phrase exceptions (e.g. 妈妈的朋友 → sometimes 妈妈朋友 in very colloquial or specific patterns), but 自己的钱包 is not one of them. So you need 的 here.

Why use 自己 instead of just 他的钱包?

自己 is a reflexive pronoun, usually referring back to the subject of the clause.

他的钱包 – his wallet (refers to “his” in a straightforward way)
自己的钱包 – his own wallet (if the subject is 他)

Using 自己 here emphasizes that the wallet belongs to him himself, not to someone else.

In this sentence, both are grammatically fine:

他找不到他的钱包了
他找不到自己的钱包了

But 自己的钱包 slightly highlights the reflexive relationship and can feel a bit more natural or focused in this context: he can’t find his *own wallet* (not, say, his friend’s wallet).

What is the role of the comma between 钱包了 and 很不高兴? Could we say it all without a pause?

The comma is separating two clauses:

他找不到自己的钱包了 – He can’t find his wallet (now).
很不高兴 – (He is) very unhappy.

In spoken Chinese, you’d naturally pause slightly between these two ideas. Writing them together without a connector:

他找不到自己的钱包了很不高兴。

is not natural; the second part needs either:

A subject: 他很不高兴。
Or to be clearly attached with something like 所以 (so):
- 他找不到自己的钱包了，所以很不高兴。

In everyday writing, using a comma and omitting the second 他 is very common:

他找不到自己的钱包了，很不高兴。

It’s understood that 很不高兴 describes 他.

Could we change the word order to 他自己的钱包找不到了，很不高兴? Is that correct?

Yes, 他自己的钱包找不到了，很不高兴 is grammatically correct.

The differences in feel:

他找不到自己的钱包了 – more neutral and common word order: Subject + Verb + Object.
他自己的钱包找不到了 – brings 他自己的钱包 to the front, putting more focus on the wallet itself (“his own wallet can’t be found”).

Both are natural. The original sentence simply uses the most common structure.

What would change if we removed 了 and said 他找不到自己的钱包，很不高兴?

Without 了, you still get a fully grammatical sentence:

他找不到自己的钱包，很不高兴。

The difference is subtle:

With 了:
- 他找不到自己的钱包了 suggests a new or resulting state: “Now he (has ended up in a situation where he) can’t find his wallet.”
Without 了:
- More of a plain description: “He can’t find his wallet.”
- Slightly less emphasis on the idea of a change or newly discovered situation.

In context where he has just discovered the wallet is missing or has just finished searching, 了 feels especially appropriate.

Why isn’t there a measure word before 钱包? Shouldn’t it be 一个钱包?

Yes, you can say 一个钱包:

他找不到自己的一个钱包了。 – He can’t find one (particular) wallet of his.

But in this sentence, 钱包 refers to a specific, known wallet (his own wallet), and in such cases, especially with a possessor + 的, Chinese often drops the measure word:

我的钱包 – my wallet
他的钱包 – his wallet
自己的钱包 – one’s own wallet

Because 他 only has one main wallet in this context, 自己的钱包 is naturally interpreted as “his wallet” without needing 一个. Adding 一个 would sound like you’re emphasizing the number (“one wallet”) or distinguishing it from other possible wallets.

Does 自己 always refer to the subject? In 他找不到自己的钱包了, could 自己 mean someone else?

In standard usage, 自己 normally refers back to the subject of the clause.

Here:

Subject: 他
Reflexive: 自己
So 自己的钱包 = his own wallet.

In more complex sentences with multiple possible antecedents, context can sometimes create ambiguity, but in a simple sentence like this, 自己 is interpreted as referring to 他 by default. It would not naturally be taken to mean someone else’s “self.”