Learn Hardcore Spanish (Spain): Se acabó el pan, así que compraré más mañana. - We ran out of bread, so I will buy more tomorrow.

Acabarse + noun means “to run out (of something)” or “for something to be used up.”
Se here isn’t reflexive; it’s a pronominal/anticausative marker that removes the agent: “The bread ran out.”
You wouldn’t normally say “Someone finished the bread” unless you name the person.

Why is the verb singular (se acabó)?

Because the grammatical subject is el pan (singular), so the verb is 3rd person singular preterite: acabó. If the subject were plural, the verb would agree: Se acabaron los huevos.

What’s the difference between Se acabó el pan and Se ha acabado el pan in Spain?

Se ha acabado (present perfect) is very common in Spain for events within “today/this period” or just now.
Se acabó (preterite) places it in a finished past timeframe or sounds more narrative/plain.
Both are heard; choice depends on context and regional habits.

Can I say El pan se acabó instead?

Yes. Both Se acabó el pan and El pan se acabó are correct. Keeping the subject (el pan) at the end is very common when presenting new information; fronting it highlights “the bread” as the topic.

Why do we say and not just ?