"Ĉu vi scias, kiam la vintro komenciĝas?"

Translation: Do you know when the winter begins?

[Parsneps]

La vintro venas

[Aramande]

Veku min, kiam septembro finas.

[salivanto]

... kiam septembro finigxos.

[hellomidnight]

Do you have to put 'la' in front of a season, as in French, or can you just say "kiam vintro komenciĝas"?

[noureddin95]

In general yes. But not always.

Zamenhof used both "en somero" and "en la somero". In PIV all the examples about "vintro" use "la" except one: "kio taŭgas por somero, ne taŭgas por vintro".

[Criculann]

So is there are a rule or is it just that "la somero/vintro/..." is more common?

[noureddin95]

PIV didn't explain the difference(s). So, I went to PMEG.

PMEG says that seasons and day-parts are ordinary nouns, and one uses "la" totally according to the rules for the ordinary nouns.

See the examples here (the 4th paragraph).

[Criculann]

Dankon!

[person594]

Is there a difference in meaning between komenciĝas and komencas? As I understand it, komenci = to begin, and -iĝi means to begin doing something, so wouldn't komenciĝi mean to begin beginning?

[VincentOostelbos]

The -iĝ suffix can be thought of as something like "to become"; something that turns an active verb into a passive, and thus a transitive verb into an intransitive one. Komenci = to begin (something); komenciĝi = to become begun. The latter would also be written as just "to begin" in English, but hopefully this still makes the distinction a bit clearer.

[Luis_Domingos]

It's actually the other way around: "komenci" is used in a transitive way (to begin something), while "komenciĝi" is used as the intransitive (to begin).

[Ruaidhr1]

En Irlando, vi scias ke vintro komencas cxar la pluvo farigxas pli malvarma!

[BossLearner87]

Ne, cxar mi scias nenio, cxar mi estas jo snow