Learn Turkish: Ben astronot olurdum. - I would be an astronaut.

The verb olurdum has the aorist ending -ur. I thought the aorist was used for general facts or habits in the present. Why does it mean "would be" here?

Look closely and you'll see a second time marker: the past tense -du. When you combine the aorist (-ur) with the past tense (-du), it creates a new meaning. This combination is often used to express a hypothetical "would" (as in "I would be an astronaut if I had the choice").

Could olurdum also mean "I used to be"?

Yes, it absolutely can! The combination of the aorist and past tense (-urdu) is used for both hypothetical situations ("would do") and past habits ("used to do"). Context is the only way to know if the speaker means "I used to be an astronaut" or "I would be an astronaut."

The English translation says "an astronaut". Why isn't there a word for "an" in the Turkish sentence?

In Turkish, when talking about professions, categories, or identities, the indefinite article bir is usually dropped. Just like you say Öğretmenim (I am a teacher) instead of Ben bir öğretmenim, you simply say astronot olurdum rather than bir astronot olurdum.

I learned that olmak means "to become". Could this also translate to "I would become an astronaut"?

Yes, that is a perfectly valid translation! In Turkish, the verb olmak covers both "to be" and "to become". When talking about a future or hypothetical career, English speakers often use "be", but translating it as "become" captures the meaning just as well.