Learn Hardcore Turkish: Bu soruyu Türkçe cevaplayabilmek istiyorum. - I want to be able to answer this question in Turkish.

Bu – this
soruyu – question with accusative ending: soru (question) + -yu (definite object) → this question (as a specific object)
Türkçe – in Turkish (literally “Turkish”, used adverbially)
cevaplayabilmek – to be able to answer
- cevapla- – to answer
- -yAbil- – can / to be able to
- -mek – infinitive ending to …
istiyorum – I want (present continuous form, but often just “I want” in English)

So literally: Bu (this) soruyu (the question-ACC) Türkçe (in Turkish) cevaplayabilmek (to be able to answer) istiyorum (I want).

Why is it soruyu and not just soru?

Because in Turkish, a specific, definite direct object usually takes the accusative case.

soru – a question / question (in general)
soruyu – the question / this question (definite, known which one)

Formed as:

soru
- (y)u → soruyu

The -u is the accusative ending, and y is a buffer consonant to make pronunciation smoother (soru-u → soruyu).

You use accusative when:

The object is specific:
- Bu soruyu anlıyorum. – I understand this question.
You would say “the / this / that” in English.

So Bu soruyu = this (specific) question as the direct object of cevaplamak (to answer).

Why is it Türkçe and not Türkçeyi or Türkçe olarak?

Here Türkçe is used adverbially, meaning “in Turkish”.

Türkçe can mean:
- Turkish (language) – as a noun
- in Turkish – as an adverb

In your sentence:

Bu soruyu Türkçe cevaplayabilmek istiyorum.
→ I want to be able to answer this question in Turkish.

We do not need an object marker here, because Türkçe is not an object; it describes how the question is answered (the manner / language).

Alternatives:

Türkçeyi – would make Türkçe into a definite object; that would suggest something like “I want to be able to answer this question, (the thing called) Turkish”, which is wrong here.
Türkçe olarak – literally “as Turkish / in a Turkish way”. Possible, but more formal / heavier than needed. Simple Türkçe is most natural.

So Türkçe = in Turkish (adverbial use), which is exactly what we need.

What does the -abilmek part in cevaplayabilmek mean?

The chunk -Abil- (written -abil- / -ebil- depending on vowel harmony) is the ability / possibility suffix.

Structure:

cevapla- – to answer
-yAbil- – can, to be able to
-mek – infinitive (to …)

So:

cevaplamak – to answer
cevaplayabilmek – to be able to answer, to manage to answer

Meaning difference:

Bu soruyu Türkçe cevaplamak istiyorum.
→ I want to answer this question in Turkish. (focus on the act of answering)
Bu soruyu Türkçe cevaplayabilmek istiyorum.
→ I want to be able to answer this question in Turkish. (focus on the ability / skill / success)

In many contexts, -ebilmek implies:

having the skill / knowledge
having the opportunity
managing despite difficulty

Why is cevaplayabilmek in the infinitive form with -mek?

In Turkish, when you use istemek (to want), the verb you want to do normally appears in the infinitive:

… yapmak istiyorum. – I want to do …
… gitmek istiyorum. – I want to go …
… öğrenmek istiyorum. – I want to learn …

So:

cevaplayabilmek is the infinitive: to be able to answer
istiyorum is the conjugated main verb: I want

Pattern:

[Infinitive] + istiyorum = I want to …

Therefore:

cevaplayabilmek istiyorum = I want to be able to answer.

Why is the verb istiyorum at the end of the sentence?

Because Turkish is normally SOV (Subject–Object–Verb):

Subject → Ben (I) – usually omitted because it’s in the verb ending
Object → Bu soruyu (this question)
Adverbial / manner → Türkçe (in Turkish)
Verb → cevaplayabilmek istiyorum (I want to be able to answer)

So the neutral order is: > [Subject] – [Object] – [Other info] – [Verb]

Putting istiyorum at the end is the standard, natural position.

Other orders are possible for emphasis, but:

Bu soruyu Türkçe cevaplayabilmek istiyorum.
is the neutral, most common arrangement.

Could we say Ben bu soruyu Türkçe cevaplayabilmek istiyorum? Do we need ben?

You can say Ben bu soruyu Türkçe cevaplayabilmek istiyorum, and it’s grammatically correct, but ben is not necessary.

In Turkish:

The verb ending -um in istiyorum already shows the subject “I”.
Personal subject pronouns (ben, sen, o, …) are usually omitted unless you want emphasis or contrast.

So:

Bu soruyu Türkçe cevaplayabilmek istiyorum.
– normal, neutral, “I want to be able to answer this question in Turkish.”
Ben bu soruyu Türkçe cevaplayabilmek istiyorum (başkaları değil).
– I want to be able to answer this question in Turkish (not others).
Here ben is stressed.

What exactly is the difference between cevaplamak and cevap vermek?

Both are used for answering, but their structure is different:

cevaplamak – a simple verb “to answer”
- Takes a direct object in accusative:
  - Bu soruyu cevapladım. – I answered this question.
cevap vermek – literally “to give an answer”
- A light-verb construction: cevap (answer) + vermek (to give)
- Usually takes dative for the thing you answer:
  - Bu soruya cevap verdim. – I gave an answer to this question.

Both are correct and common. With your sentence, you can say:

Bu soruyu Türkçe cevaplayabilmek istiyorum.
Bu soruya Türkçe cevap verebilmek istiyorum.

Same meaning, slightly different construction:

soruyu + cevaplamak
soruya + cevap vermek

Why is soruyu with -u, not -ı or -i? How does that work?

This is vowel harmony in the accusative ending.

The accusative has four possible forms:

-ı, -i, -u, -ü

Which one you use depends on the last vowel of the noun:

Last vowel a, ı → -ı
Last vowel e, i → -i
Last vowel o, u → -u
Last vowel ö, ü → -ü

The word soru ends in u, so we choose -u:

soru
- (y)u → soruyu

The y is a buffer consonant used when a suffix starting with a vowel is attached to a word ending in a vowel (to avoid a vowel-vowel clash).

Is Türkçe an adjective, a noun, or an adverb here?

In this sentence, Türkçe functions as an adverb:

It modifies the verb cevaplayabilmek and tells us how / in what language the action is done: answer in Turkish.

But grammatically, Türkçe is a flexible word that can be:

a noun:
- Türkçe öğreniyorum. – I’m learning Turkish.
an adjective:
- Türkçe kitap – a Turkish (language) book
an adverb:
- Türkçe konuşuyor. – He/She is speaking in Turkish.

In Bu soruyu Türkçe cevaplayabilmek istiyorum, it is adverbial: in Turkish.

Could we say Bu soruyu Türkçe cevaplamak istiyorum without -ebilmek? How would the meaning change?

Yes, you can, and it’s perfectly correct:

Bu soruyu Türkçe cevaplamak istiyorum.
→ I want to answer this question in Turkish.

Meaning difference:

cevaplamak istiyorum – I want to do the act of answering.
cevaplayabilmek istiyorum – I want to be able to answer (have the necessary skill, knowledge, opportunity).

So with -ebilmek, you emphasize:

ability / skill (e.g., “My Turkish isn’t good yet; I want to be able to answer it.”)
or the idea of managing / succeeding in answering.

Why is istiyorum in the present continuous form, not a simple present like in English “I want”?

Turkish uses the -iyor form (istiyorum) both for:

Present continuous (I am wanting right now)
and a kind of present / near-future desire (I want, I would like)

The simple present of istemek (isterim) is either:

more formal, or
used for general, habitual preferences:
- Çayı şekerli isterim. – I (generally) like my tea with sugar.

In everyday speech, for a current wish or plan, people almost always say:

istiyorum – I want
yapmak istiyorum, gitmek istiyorum, öğrenmek istiyorum, etc.

So:

Bu soruyu Türkçe cevaplayabilmek istiyorum.
is the natural way to say “I want to be able to answer this question in Turkish.” in modern Turkish.