fāshēng le shénme?

发生 means to happen or to occur.

In 发生了什么？, it is the main verb of the sentence:

• 发生 = happen
• 了 = marks that something occurred
• 什么 = what

So the whole sentence means What happened?

A useful point: 发生 is a fairly neutral, standard verb. It can be used for all kinds of events:

• 发生了事故。 = An accident happened.
• 发生了变化。 = A change occurred.

In this sentence, 了 shows that an event has occurred or came about. It gives the sense of something happened rather than just talking about the general idea of happening.

So:

• 发生什么？ can sound incomplete or less natural in most normal situations.
• 发生了什么？ is the usual way to ask What happened?

Here, 了 is not exactly the same as the English past tense, but in this sentence it does help give a completed-event feeling.

In Mandarin, question words usually stay in the same position where the answer would go. They do not usually move to the front like in English.

Compare:

• Statement: 发生了事情。 = Something happened.
• Question: 发生了什么？ = What happened?

The word 什么 stays where the unknown thing belongs.

This is a very important Mandarin pattern:

• 你喜欢什么？ = What do you like?
• 他去哪儿？ = Where is he going?

So 发生了什么？ is normal Mandarin word order.

Usually, no. 什么发生了？ is not the normal way to ask What happened?

Mandarin does not usually front the question word the way English does. So the natural form is:

• 发生了什么？

If you say 什么发生了？, it sounds unnatural in most contexts.

Yes, in a way. Mandarin often leaves out subjects when they are obvious or unnecessary.

In English, we say What happened? without naming a subject. Mandarin works similarly here. The sentence does not need a subject like it.

So 发生了什么？ is already complete and natural.

If needed, you can add context:

• 这里发生了什么？ = What happened here?
• 昨天发生了什么？ = What happened yesterday?
• 你们之间发生了什么？ = What happened between you two?

A helpful rough breakdown is:

• 发生 = happen
• 了 = completed-occurrence marker
• 什么 = what

A very literal gloss would be something like:

• Happened what?

That sounds strange in English, but it matches normal Mandarin structure.

The key grammar pattern is:

• Verb + 了 + 什么

when you are asking what happened / what was done / what occurred.

The pinyin is:

• 发生了什么
• fāshēng le shénme

A few pronunciation notes:

• 发 = fā with first tone
• 生 = shēng with first tone
• 了 here is usually a light tone: le
• 什 in 什么 is usually pronounced shén
• 么 is usually a light tone: me

So natural speech sounds like:

• fāshēng le shénme

Not every syllable is equally stressed. 了 and 么 are usually light and quick.

Because this 了 is the common grammatical particle that marks a completed event, and that particle is pronounced le.

Mandarin has another character pronunciation liǎo, but that is used in different words and meanings, not in this sentence.

So here:

• 发生了什么？
• 了 = le

This is the standard pronunciation.

Yes. 发生 is neutral. It can describe good, bad, or neutral events.

Examples:

• 发生了好事。 = A good thing happened.
• 发生了意外。 = An accident happened.
• 发生了变化。 = A change happened.

That said, in everyday speech, 发生了什么？ is often used when something seems unusual, unexpected, or possibly wrong, because people usually ask it when they notice a problem or surprise. But the verb itself is neutral.

Both can be translated as What happened?, but they are used a little differently.

发生了什么？

• more literal: What happened?
• asks about an event or situation
• can sound a bit more neutral or formal

怎么了？

• often means What’s wrong?, What happened?, or What’s the matter?
• very common in conversation
• often used when you notice someone is upset, something is strange, or there is a problem

Examples:

• You hear a loud noise: 发生了什么？
• Your friend looks worried: 你怎么了？

Sometimes both work, but the feeling is slightly different.

Yes. 发生了什么？ is natural in both spoken and written Mandarin.

It is:

• common in everyday conversation
• normal in news or narration
• easy to understand
• not overly formal, but not slang either

So it is a very useful sentence to learn.

发生 is often used without a direct object in the way English uses one. It usually talks about an event occurring.

Common patterns include:

• 发生了什么？ = What happened?
• 发生了事故。 = An accident happened.
• 发生变化。 = Changes occur.

It often works with nouns that describe events, situations, or changes.

A very common pattern is:

• 在 + place/time + 发生
  • 昨天发生了什么？ = What happened yesterday?
  • 这里发生了什么？ = What happened here?

So learners should think of 发生 more as occur/happen than as a verb that takes a typical direct object like eat or see.

Yes. 出了什么事？ is another very common way to ask What happened?

The feeling is slightly different:

• 发生了什么？ = more neutral, general
• 出了什么事？ = often suggests that something went wrong or some incident occurred

Examples:

• 发生了什么？ = What happened?
• 出了什么事？ = What happened? / What went wrong?

So if you want the broadest and safest expression, 发生了什么？ is excellent. If the situation sounds more like trouble, 出了什么事？ is also very natural.

A few common mistakes are:

1. Putting the question word at the front

   • Incorrect: 什么发生了？
   • Correct: 发生了什么？

2. Leaving out 了 in a normal past event question

   • Less natural in most contexts: 发生什么？
   • Natural: 发生了什么？

3. Pronouncing every syllable with equal stress

   • Natural speech usually makes 了 and 么 light:
   • fāshēng le shénme

4. Using English word order instead of Mandarin word order

   • Mandarin keeps 什么 in place rather than moving it to the front

If you remember question words stay in place and 了 marks the occurrence of the event, this sentence becomes much easier to understand.