Teyzem çantasına bir hırka koydu, çünkü gece rüzgâr olabilir.

Yes. Teyze specifically means maternal aunt—your mother’s sister. That is different from hala, which means paternal aunt—your father’s sister.

In everyday Turkish, teyze can also be used for an older woman in a friendly or respectful way, but in this sentence it clearly means aunt.

Turkish often shows possession with a suffix attached directly to the noun.

• teyze = aunt
• teyzem = my aunt

The -m here means my.

So instead of saying something like my aunt with a separate word, Turkish packs that meaning into the noun itself.

Çantasına can be broken down like this:

• çanta = bag
• -sı = his/her/its (3rd person possessive)
• -na = to / into (dative, with a buffer n)

So:

• çantasına = into her bag / to her bag

In this sentence, it refers to your aunt’s bag, so the possessive is understood from the context.

Because Turkish often marks possession directly on the noun.

So English says:

• her bag

Turkish can simply say:

• çantası = his/her bag

And in this sentence:

• çantasına = into his/her bag

The owner is understood from context. Since the subject is teyzem, we naturally understand this as my aunt’s bag.

If you wanted to be extra explicit, you could say:

• teyzemin çantasına = into my aunt’s bag

But that is not necessary here.

Because the verb koymak means to put/place, and that usually involves movement into or onto somewhere. Turkish uses the dative for the destination.

• çantasına = into/to her bag
• çantasında = in/on/at her bag

So:

• çantasına koydu = put into her bag
• çantasında would mean something like in her bag, describing location rather than destination

This is a very common pattern in Turkish:

• masaya koydu = put it on the table
• cebime koydu = put it in my pocket

This is about the Turkish accusative.

• bir hırka = a cardigan / some cardigan, non-specific
• hırkayı = the cardigan, specific/known

In Turkish, a direct object often takes the accusative only when it is specific.

So here:

• bir hırka koydu = she put a cardigan in
  • not a specific, already identified cardigan

If you said:

• hırkayı koydu

that would mean something more like:

• she put the cardigan in

with a definite, known cardigan.

Here, bir means a/an.

• bir hırka = a cardigan

Turkish uses bir both for:

1. the number one
2. the indefinite article idea a/an

Usually context tells you which meaning is intended. In this sentence, it simply means a cardigan, not specifically one cardigan with numerical emphasis.

Hırka usually means a cardigan or a light knitted outer layer. It is softer and lighter in feel than words like kazak (sweater/jumper).

So bir hırka koydu suggests she put in a light extra layer of clothing, which fits the reason clause about possible wind at night.

Koydu is the simple past form of koymak (to put, to place).

Breakdown:

• koy- = put/place
• -du = past tense

So:

• koydu = put / placed

This is a completed past action: your aunt already put the cardigan in the bag.

Because gece is being used as a time expression, meaning at night / tonight / during the night, depending on context.

Turkish often uses bare time words adverbially without adding a case ending:

• bugün = today
• yarın = tomorrow
• gece = at night

So:

• çünkü gece rüzgâr olabilir = because there may be wind at night

You do not need something like gecede here.

Literally, it means something like:

• there may be wind
• it may be windy

More literally word-for-word:

• rüzgâr = wind
• olabilir = may be / can be / might be

So the sentence is expressing possibility, not certainty. Your aunt put the cardigan in her bag because wind is possible during the night.

Olabilir comes from olmak (to be, to become, to happen) and the potential form.

A useful way to see it is:

• ol- = be/become
• -abil- = can / be able to
• -ir = aorist/general tense ending

So literally it looks like can be. But in many contexts, especially with weather or general situations, this structure expresses possibility:

• yağmur olabilir = it may rain / there may be rain
• sorun olabilir = there may be a problem
• rüzgâr olabilir = there may be wind

So here olabilir is best understood as might be / may be.

Because Turkish normally prefers verb-final word order.

In the main clause:

• Teyzem çantasına bir hırka koydu
• literally: My aunt into-her-bag a cardigan put

In the reason clause:

• çünkü gece rüzgâr olabilir
• literally: because at night wind may-be

This is very normal in Turkish. Even when the word order feels unusual from an English point of view, the final verb is one of the most important patterns to get used to.