The phrase "what happened?" in Spanish can be translated in several ways, with the most common being:

• ¿Qué pasó? - This is the simple past form and the most direct translation of "what happened?" It uses the preterite tense of the verb pasar (to happen) and is used to ask about something that occurred in the past

• ¿Qué sucedió? - Another formal way to say "what happened?" using the verb suceder (to occur/happen) in the preterite tense

• ¿Qué ha pasado? - This is the present perfect form, meaning "what has happened?" It uses the auxiliary verb haber plus the past participle pasado and often implies a recent or relevant past event

In everyday conversation, ¿Qué pasó? is the most frequent and natural way to ask "what happened?" in Spanish

Additional notes on usage:

• Pasó is the third-person singular preterite form of pasar and functions as a verb here, not a pronoun plus verb. The question word qué ("what") acts as the subject of the verb

• Pasado is the past participle and requires an auxiliary verb (e.g., haber) to form the perfect tense, hence ¿Qué ha pasado? means "what has happened?"

Summary of common translations:

English| Spanish| Explanation
---|---|---
What happened?| ¿Qué pasó?| Simple past, most common usage
What happened?| ¿Qué sucedió?| Formal, using verb suceder
What has happened?| ¿Qué ha pasado?| Present perfect, recent events

These phrases are interchangeable depending on context and formality, but ¿Qué pasó? is the standard everyday question for "what happened?"