Learn Hardcore Turkish: Siz yarına randevu almak üzere çağrı merkezini arar mısınız? - Would you call the call center in order to make an appointment for tomorrow?

The aorist + question form (V-(A)r mısınız?) is a standard polite request in Turkish, roughly “Would you …?”
Imperative (Arayın) is direct; adding lütfen softens it, but it’s still more commanding.
Future + question (Arayacak mısınız?) asks about someone’s plan/intent (“Are you going to call?”), not a request.
So Arar mısınız? is the default polite “Would you call …?”

Is "Siz" necessary here?

No. Pronouns are usually dropped because person is marked on the verb or the question particle.
Siz adds clarity/emphasis or extra politeness/formality.
Without it, Yarına … arar mısınız? is still clearly addressing “you (formal/plural)” because of -mısınız.

What exactly is "mı/mi/mu/mü," and why is it "mısınız" here?

mi/mı/mu/mü is the yes–no question particle. It obeys vowel harmony and is written separately.
It can take person endings in questions: gelir miyim / misin / mi / miyiz / misiniz / mi(ler)?
Here, the last vowel in arar is a, so we use mı: arar mı-.
Then add the 2nd person plural/respect ending: -sınız → arar mısınız.

How is "arar mısınız" formed morphologically?

Why is it "yarına" and not just "yarın" or "yarın için"?

yarına is the dative (-a) used with time to mean “for (as the target time)”: “an appointment for tomorrow.”
yarın alone would mean “tomorrow” as an adverb of time (“call tomorrow”), which is a different meaning.
yarın için is also fine and common; it’s a bit more neutral/colloquial than yarına. All of these are natural:
- yarına randevu almak
- yarın için randevu almak

What does "-mek üzere" add here? Can I replace it with "için"?

-mek/-mak üzere = “in order to / with the aim of,” slightly formal/official-sounding.
için is the everyday “for/to” in purpose clauses.
Both are correct: randevu almak üzere ≈ randevu almak için. The üzere version feels a bit more formal/polished.

Why is "çağrı merkezini" in the accusative (-ni)? Could it be "çağrı merkezi"?

aramak takes a direct object in the accusative when the object is specific/definite.
çağrı merkezini implies a particular, known call center (e.g., the company’s call center).
Bare çağrı merkezi (no -i) would be an indefinite object (“a call center”), which sounds odd here because you presumably mean a specific one.

What’s inside "çağrı merkezini" morphologically?

çağrı merkezi is an indefinite noun–noun compound (“call center”): merkez + 3rd person possessor marker -(s)i → merkezi.
Then add the accusative -i to mark a definite object: merkez + i → already has -(s)i, so the stacked result is merkez-i + (Acc) -ni → merkezi-ni.
So: çağrı merkezini = “the call center” (as a definite object).

Can I say "çağrı merkezine arar mısınız?" with -e?

No with aramak. The verb aramak takes a direct object (accusative), not a dative target.
If you switch to telefon etmek, then you use dative: Çağrı merkezine telefon eder misiniz?

Is "Arayabilir misiniz?" better than "Arar mısınız?" for a request?

Both are polite. Nuance:
- Arar mısınız? = “Would you call …?” neutral–polite request.
- Arayabilir misiniz? = “Could you call …?” sometimes feels a touch softer or more tentative.
Either is fine in most contexts.

Is the word order fixed? Where else can I put "yarına" or the purpose phrase?

Turkish word order is flexible; the predicate typically comes last. Natural variants:
- Yarına randevu almak üzere çağrı merkezini arar mısınız? (Time early, purpose before object—very natural)
- Çağrı merkezini yarına randevu almak üzere arar mısınız? (Object before purpose)
- Randevu almak üzere yarına çağrı merkezini arar mısınız? is less common; keep time near the start for clarity.
Moving elements mainly changes emphasis, not core meaning.

Could I use the present continuous question "arıyor musunuz" to make this request?

Not for a polite request. Arıyor musunuz? asks “Are you calling (now)?”—it’s about ongoing action.
For requests, use:
- Arar mısınız (lütfen)?
- Arayabilir misiniz (lütfen)?
- Or the polite imperative: Lütfen arayın.

How formal is this sentence, and how could I make it softer or more direct?

Current sentence is polite and slightly formal (due to Siz and -mek üzere).
Softer/more tentative: add lütfen, or use potential: Çağrı merkezini … arayabilir misiniz, lütfen?
Extra-polite/hypothetical: … arar mıydınız?
More direct: Yarına randevu almak için çağrı merkezini arayın, lütfen.

Do I need "bir" before "randevu"?

No. Turkish often omits the indefinite article when it’s obvious.
bir randevu is okay if you want to stress “a single appointment” or introduce it as new information, but it’s not required.

What’s the difference between "yarına randevu almak" and saying "yarın … arar mısınız"?

yarına randevu almak = “to book an appointment for tomorrow” (the appointment date is tomorrow; the call is now).
yarın … arar mısınız? = “Would you call tomorrow …?” (the call time is tomorrow), which changes the meaning.

Any pronunciation tips for "çağrı" and "mısınız"?

ğ in çağrı isn’t a hard g; it lengthens the preceding vowel: roughly “chaa-rı.”
ı is the dotless i, a close back unrounded vowel (like a relaxed ‘uh’); in mısınız both ı’s are that sound.
The question particle mı/mi/mu/mü typically carries the sentence stress: arar mısınız?

How would I negate this politely?

For a polite negative instruction: Lütfen çağrı merkezini aramayın.
To suggest refraining (soft): Çağrı merkezini aramasanız daha iyi olur.
Negative questions like Aramaz mısınız? can sound confrontational (“Won’t you call?”), so use with care.