Learn Hardcore Turkish: Kız kardeşim de tarak kullanıyor, çünkü kısa saçını düzenlemek istiyor. - My sister also uses a comb because she wants to tidy her short hair.

kız kardeş = female sibling, “sister.”
Add 1st person singular possessive -im: kız kardeş-im → kız kardeşim = “my sister.” It explicitly says a female sibling. Related words: erkek kardeş (brother), abla (older sister), ağabey/abi (older brother).

What does de mean here, and why is it after kız kardeşim?

de/da is the enclitic meaning “also/too.” It’s written as a separate word and placed immediately after the element you want to mark as “also.”

Kız kardeşim de tarak kullanıyor: My sister also uses a comb (someone else does too).
Kız kardeşim tarak da kullanıyor: She uses a comb as well (in addition to something else, like a brush).

Form choice: after a front vowel use de, after a back vowel use da (no consonant change to te/ta for the enclitic).

How is this de different from the locative suffix -de/-da?

The enclitic de/da (“also”) is written separately: ben de = “me too.”
The locative -de/-da (“in/at/on”) is attached to the noun and can harden to -te/-ta after certain consonants: bende = “on/with me,” evde = “in the house,” saatte = “on the clock.” Meaning can change drastically:
ev de = “the house too”
evde = “in the house”

Why is it tarak and not tarağı?

tarak is an indefinite direct object (“a comb”), so it stays bare (no accusative). If you mean a specific/known comb, you use the accusative: tarağı (“the comb”). Note the regular consonant softening: tarak + -ı → tarağı.

What exactly is going on morphologically in kısa saçını?

kısa: “short” (adjective)
saç: “hair” (noun)
3rd person possessive -ı: saç-ı = “his/her hair”
Accusative -ı with buffer -n (to separate vowels): saç-ı-nı = “his/her hair” as a definite object So kısa saçını = “her short hair” (definite, possessed).

Why is it 3rd person possessive (saçını) when the subject is “my sister”?

Because the hair belongs to “her” (the third person, i.e., your sister), not to the speaker. In Turkish, a possessed noun referring to the subject is commonly marked with 3rd person possessive:

Kız kardeşim saçını… = “My sister [her own] hair…” If you want to emphasize it’s her own hair (not someone else’s), you can add kendi: Kız kardeşim kendi saçını…

Why is it düzenlemek istiyor and not düzenlemeyi istiyor?

With istemek, the default and most natural complement is the bare infinitive -mek/-mak: düzenlemek istiyor (“wants to arrange”). The -meyi/-mayı form turns the action into a definite noun phrase and is used when you want to focus on or modify the action itself; it’s possible but less common/neutral here. Use -meyi when the act is being specifically emphasized: Bunu düzenlemeyi çok istiyor (“He really wants to do this arranging”).

Could this sentence mean “She wants to make her hair short”?

No. kısa saçını means “her short hair” (adjective + noun). “To make her hair short” would be saçını kısaltmak (shorten): Saçını kısaltmak istiyor.

Why is there a comma before çünkü? Can çünkü start a sentence?

çünkü (“because”) typically introduces the reason clause, and a comma before it is normal: main clause, çünkü reason. Starting a sentence with Çünkü is common in speech to give a reason for the previous sentence, but in formal writing you often keep it after the main clause or use other structures (e.g., -DIĞI için, bu yüzden).

Are there other natural ways to say “because” here?

Yes:

Subordinator -DIĞI için: Kız kardeşim kısa saçını düzenlemek istediği için tarak kullanıyor.
Causal phrase -den dolayı: Kısa saçından dolayı tarak kullanıyor.
Result connector bu yüzden (“therefore/so”): Kısa saçını düzenlemek istiyor, bu yüzden tarak kullanıyor.

How is kullanıyor formed, and what does it convey?

Stem: kullan- (“use”)
Present continuous: -(I)yor → kullan-ıyor It conveys an ongoing/current action or a present situation: “is using/uses (currently).” Similarly, istiyor = iste- + -(I)yor (“wants [now/at present]”).

When would I use kullanır instead of kullanıyor?

kullanır is the aorist (habitual/generic): “(generally) uses.” Use it for routines or timeless facts:

Genelde tarak kullanır = “She generally uses a comb.” kullanıyor focuses on what is happening now or around now.

Why is the verb at the end in çünkü kısa saçını düzenlemek istiyor?

Turkish is typically SOV (Subject–Object–Verb). In the reason clause:

Object: kısa saçını
Verbal complement: düzenlemek
Finite verb: istiyor So the verb naturally appears at the end.

How should I pronounce the tricky letters here (ı, ç, ş, ü)?

ı (dotless i): a close back unrounded vowel; like the second vowel in “roses” in many accents, or a relaxed “uh” but tighter (e.g., kısa, saçını).
i (dotted i): as in “machine.”
ç: “ch” (e.g., çünkü, saç).
ş: “sh” (e.g., kardeşim, saç).
ü: front rounded “u,” like German “ü” or French “u” (e.g., çünkü).

Could I say düzenlemek vs düzeltmek or even taramak here?

Yes, with nuance:

düzenlemek: arrange/neaten (more general).
düzeltmek: fix/correct/neaten (often a bit more “fixing”).
saçını taramak: to comb her hair (directly names the action with a comb). All can fit, depending on what you want to emphasize:
… tarak kullanıyor, çünkü saçını taramak istiyor.
… çünkü kısa saçını düzeltmek/düzenlemek istiyor.

Where is the pronoun “she” in Turkish? Should I add o?

You don’t need it. Turkish is pro-drop: the subject is recoverable from context and verb morphology. Kız kardeşim … istiyor already identifies the subject; adding o is usually unnecessary unless you need contrast or emphasis.