What happened vs Why'd this happen

When to use each in English, with meaning, register, and examples.

What happened

Top 2,000 (common)

Why'd this happen

InformalTop 2,000 (common)
Most formal: What happened
 What happenedWhy'd this happen
Pronunciation🇬🇧 //wɒt ˈhæp.ənd//🇺🇸 //wɑt ˈhæpənd//🇬🇧 //waɪd ðɪs ˈhæpən//🇺🇸 //waɪd ðɪs ˈhæpən//
MeaningAsk someone about an event or situation.A way to ask why something occurred.
ExampleCan you tell me what happened during the meeting?Why'd this happen during the meeting?
RegisterNeutralInformal
How commonTop 2,000 (common)Top 2,000 (common)
Collocationswhat happened next, what happened then, can you tell me what happenedask why'd, wonder why'd, think why'd
AntonymsWhat will happen, What is going to happen, What occurs next-
Common mistakesConfused with 'what's happening?' which refers to current events., Using it to ask about an ongoing situation instead of a past event., Inappropriately using 'happened' in place of 'has happened' in some contexts.Using 'why did this happen' in an informal context instead., Not using the contraction correctly (e.g., saying 'why did' instead of 'why'd').
Usage notesUse in conversations to inquire about past events. Suitable in both formal and informal settings.Usually used in casual conversations. Avoid in formal writing or discussions.

See it in real clips

What happened
Why'd this happen

Frequently asked questions: What happened vs Why'd this happen

What's the difference between What happened and Why'd this happen?

What happened: Ask someone about an event or situation. Why'd this happen: A way to ask why something occurred.

Which is more formal: What happened and Why'd this happen?

What happened is the most formal of these.

Can you show an example of each?

What happened: Can you tell me what happened during the meeting? Why'd this happen: Why'd this happen during the meeting?

Can I use What happened and Why'd this happen interchangeably?

Not always. What happened and Why'd this happen are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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