Learn Hardcore Turkish: Projeyi aylardır aynı tempoda sürdürdük; artık sadece ince ayar kaldı. - We have maintained the project at the same pace for months; now only fine-tuning remains.

Projeyi = proje + y + i (buffer y
- accusative -i by vowel harmony).
You use accusative when the object is definite/specific.
Contrast:
- Projeyi sürdürdük = We kept the project going (that particular project).
- Bir proje sürdürdük = We kept a project going (non-specific).

Could I say Projeye devam ettik instead? How is sürdürmek different from devam etmek?

Yes, but the structure changes because the verbs differ:

sürdürmek is transitive: Projeyi sürdürdük (we sustained/maintained it).
devam etmek is intransitive and takes dative: Projeye devam ettik (we continued with the project).
Projeyi devam ettik is ungrammatical. Nuance: sürdürmek emphasizes actively keeping something going; devam etmek emphasizes that something continues.

Why is the past tense sürdürdük used here rather than a present continuous like sürdürüyoruz?

Sürdürdük (we maintained) frames that phase as completed; it fits naturally before artık and kaldı (now only X is left). Alternatives:

Sürdürüyoruz = we are still maintaining it now (use if the same pace continues into the present).
Sürdürüyorduk = we were maintaining it (past progressive, useful in a narrative about the past).

What exactly does aylardır mean? How is it different from aylarca or aylardan beri?

aylardır = for months (often with a sense of up-to-now or up to a recent point). Structure: aylar + dır (copular particle used idiomatically with time to indicate duration).
aylarca = for months (pure duration, no inherent “up to now” feel).
aylardan beri = since months ago (from months ago until now), very close to aylardır in meaning.
bir aydır = for a month (now).

Why not just say aylar sürdürdük?

That’s not idiomatic. For durations you typically use:

aylardır (for months now)
or aylarca (for months). Plain plural aylar doesn’t by itself mean “for months.”

How does the phrase aynı tempoda work grammatically?

aynı = same
tempo = pace/tempo (loanword)
-da = locative suffix “in/at” So aynı tempoda means “at the same pace.” You could also say:
aynı hızda (at the same speed)
aynı tempoyla / aynı hızla (with the same pace/speed; instrumental nuance)

Is the da in tempoda the same as the clitic de meaning also?

No. In tempoda the -da is the locative case suffix attached to the noun (no space). The additive clitic de/da meaning “also/too” is written separately (with a space) and is not used here.

What does artık mean here, and how does it behave with negatives?

Artık means “now/at this point/by now” in affirmative contexts. With negatives it often means “no longer/anymore.”

Affirmative: Artık sadece ince ayar kaldı = now only fine-tuning is left.
Negative example: Artık vaktimiz yok = we no longer have time.

What does sadece do, and can I replace it?

Sadece focuses “only/just” on what follows. It’s placed immediately before the focused element: sadece ince ayar. Common alternatives:

yalnızca (synonym, slightly more formal)
yalnız (can mean “only,” but also “however,” so it can be ambiguous)
sırf (colloquial “just/merely,” sometimes implies “for the sake of”)

What exactly is ince ayar? Is it literal or idiomatic?

It’s a common collocation meaning “fine-tuning/fine adjustment,” used literally (e.g., calibration) and metaphorically (finishing touches). Related expressions:

ince ayar yapmak = to fine‑tune
son rötuşlar = final touches (more colloquial/visual)

Why is ince ayar unmarked (no case ending)? Should it be ince ayarı?

No ending is correct here because ince ayar is the subject of kaldı. Kalmak is intransitive and means “to remain/be left,” so the thing that remains is the subject. İnce ayarı kaldı would be ungrammatical in this structure.

Why use the past tense kaldı to talk about a current situation?

Turkish often uses simple past (-dı) to express a change of state whose result holds now. Kaldı conveys “has now become the case that only X remains.” Variants:

kalmış = apparently/it seems only X is left (evidential, report/inference)
kalıyor = is remaining (progressive; less natural for a snapshot result)

Is the semicolon necessary here? Could I use a period or a comma?

A semicolon neatly links two closely related clauses. You could also use:

A period: … sürdürdük. Artık sadece …
A comma plus a linker: … sürdürdük, bu yüzden/ve artık sadece … A bare comma is common informally but less ideal in careful writing.

Is the word order fixed? What changes with different orders?

Turkish is flexible; word order shifts focus.

Given: Projeyi aylardır aynı tempoda sürdürdük foregrounds the project.
Aylardır projeyi aynı tempoda sürdürdük highlights the duration.
Projeyi aynı tempoda aylardır sürdürdük is possible but less natural; time expressions usually come earlier. The verb typically comes last.

How is sürdürdük built morphologically? Anything to note about -d vs -t?

sür-dür-dü-k = root sür
- causative -dür (make continue) + past -di (harmonized to -dü) + 1pl -k. The past suffix is underlying -di but becomes -ti after a voiceless consonant (e.g., bak-tı-k). Here, r is voiced, so -dü is used.

Why is Projeyi spelled with a y before the ending?

Because proje ends in a vowel. Turkish inserts the buffer consonant y before vowel-initial suffixes:

proje + i → projeyi (accusative) Vowel harmony picks -i (last vowel e is front-unrounded).