Learn Hardcore Turkish: Şöminede ateş yakıyorum. - I am lighting a fire in the fireplace.

Choose -de/-da by vowel harmony: after a front vowel (e, i, ö, ü) use -de; after a back vowel (a, ı, o, u) use -da.
After a voiceless consonant (p, ç, t, k, f, h, s, ş), the initial d devoices to t: parkta, sınıfta.
Şömine ends in a front vowel (e), so it takes -de: Şöminede.

How is yakıyorum formed? Which parts mean what?

Morphology: yak- (burn/light) + -ıyor (present progressive) + -um (1st person singular) → yakıyorum.

The progressive is -(I)yor; the capital I stands for a vowel chosen by harmony.
The last vowel of the stem (a in yak-) is back and unrounded, so the suffix uses ı: -ıyor.
-um marks the subject as “I”.

Why is it -ıyor, not -iyor?

Because of vowel harmony. The progressive suffix vowel matches the last vowel of the stem:

After a/e → -iyor (e.g., geliyorum)
After ı/a → -ıyor (e.g., yakıyorum)
After o/u → -uyor (e.g., okuyorum)
After ö/ü → -üyor (e.g., yürüyorum)

Where is the subject? Do I need ben?

It’s built into the verb ending -um (“I”). You can add ben for emphasis or contrast:

Neutral: Şöminede ateş yakıyorum.
Emphatic: Ben şöminede ateş yakıyorum (I’m the one doing it).

Why doesn’t ateş have the accusative ending (-i)?

Indefinite direct objects are left bare in Turkish. Ateş here is indefinite (a fire), so no accusative. If you mean a specific, known fire, use the accusative:

Indefinite: ateş yakıyorum
Definite: ateşi yakıyorum (the fire)

Can I say Şöminede ateşi yakıyorum?

Yes, but it means you’re lighting a specific, identified fire (for example, the one we were just talking about). Without context, the bare ateş is more natural.

Can the word order change?

Yes. Turkish is flexible, and you use order to manage focus/topic:

Neutral: Şöminede ateş yakıyorum.
End-focus on place: Ateş yakıyorum şöminede.
With a definite object: Ateşi şöminede yakıyorum.
Strong focus on the object: Şöminede yakıyorum ateşi. Note: Indefinite objects (like bare ateş) typically sit just before the verb.

What’s the difference between yakmak and yanmak?

yakmak: transitive “to burn/light something” (you are the agent).
- Kâğıdı yakıyorum. (I’m burning the paper.)
yanmak: intransitive “to burn, be on fire.”
- Kâğıt yanıyor. (The paper is burning.)

How do I make it negative or ask a yes/no question?

Negative: insert -ma/-me before -yor.
- Şöminede ateş yakmıyorum.
Yes/no question: add the question clitic mi/ mı/ mu/ mü after the verb phrase, with harmony.
- 1st person: Şöminede ateş yakıyor muyum?
- 2nd person: Şöminede ateş yakıyor musun?

How do I pronounce the special letters here?

Ş = sh as in “shoe.”
ö = front rounded vowel (like German ö or French eu in “peu”).
ı (dotless i) = close back unrounded vowel (similar to the second vowel in “sofa”). Also note the capital/dotted pairings: i/İ and ı/I are different letters in Turkish.

Why is there no apostrophe before -de? I sometimes see a suffix after an apostrophe.

Apostrophes mark suffixes on proper nouns only: Ankara’da. With common nouns, you attach the suffix directly: şöminede. Also, the separate word de/da (meaning also/too) is written separately: Şöminede de…

Can I say Şömineyi yakıyorum instead?

That means you’re lighting/turning on the fireplace itself—natural for a gas fireplace. For a wood-burning fireplace, you normally light ateş: Şöminede ateş yakıyorum.

Do I need bir: Şöminede bir ateş yakıyorum?

Usually no. Bare nouns already express indefiniteness for objects. Bir can add a nuance of “one/a certain” or focus the count. Use it if you want that emphasis.

What’s the difference between yakıyorum and yakarım?

yakıyorum: present progressive (happening now, ongoing, or arranged near-future).
yakarım: simple present (habitual/general truth) or a strong assertion/promise/threat depending on context.

Does şöminede mean “in” or “on/at”? What if I want to stress “inside”?

The locative -de/-da covers in/at/on depending on the noun. With container-like nouns (like şömine), it maps to “in.” To emphasize interior, use a genitive + içinde:

Şöminede ateş yakıyorum (in the fireplace).
Şöminenin içinde ateş yakıyorum (explicitly inside the fireplace).

Can I pluralize ateş here?

Not in this sentence. Ateş yakmak is a set action. Plural ateşler exists but is used when you truly mean multiple separate fires:

Bahçede ateşler yaktılar.

Any common collocations with yakmak I should know?

ateş yakmak (make/light a fire)
sigara yakmak (light a cigarette)
ocak/şömine yakmak (light a stove/fireplace)
Older style: lamba yakmak (light a lamp); nowadays lambayı açmak (turn on the lamp) is more common.