Projeyi aylardır aynı tempoda sürdürdük; artık sadece ince ayar kaldı.

Because proje is the definite direct object of sürdürdük.

• proje = project
• projeyi = the project

In Turkish, when a direct object is specific/definite, it usually takes the accusative ending. So:

• proje sürdürdük would sound incomplete or unnatural here
• projeyi sürdürdük = we continued the project

This is very similar to the difference between a project and the project, although Turkish does not always map exactly onto English article usage.

Aylardır means for months or for months now.

It is a very common time expression in Turkish, similar to:

• günlerdir = for days
• yıllardır = for years
• haftalardır = for weeks

It comes from aylar + -dır, but as a whole it functions like a fixed adverbial expression meaning for months rather than literally they are months.

So:

• Projeyi aylardır sürdürdük = We have been carrying on the project for months

Even though sürdürdük is in the simple past, aylardır adds the sense of duration leading up to now.

Because tempoda uses the locative ending -da, meaning in/at the same pace.

• tempo = tempo, pace
• tempoda = in the pace / at the pace

So aynı tempoda sürdürmek means to continue at the same pace.

If you said tempoyu, that would make tempo the direct object, which is not what is happening here. The project is the thing being continued; the pace is the manner or condition in which it is continued.

So:

• projeyi = the object being continued
• aynı tempoda = the way it was continued

Sürdürdük means we continued, we maintained, or we kept going.

Breakdown:

• sürdürmek = to continue, maintain, carry on
• sürdürdü- = continued
• -k = we

So sürdürdük is:

• 1st person plural
• definite past tense

In this sentence, it means something like:

• We kept the project going at the same pace for months

Note that sürdürmek is a standard Turkish verb meaning to continue something. It is transitive, so it takes an object like projeyi.

Yes. They are related in meaning, but they are not used in exactly the same way.

• devam etmek often means to continue or to go on
• sürdürmek often means to continue/maintain/carry on something

A useful difference:

• Toplantı devam etti. = The meeting continued.
• Toplantıyı sürdürdük. = We continued the meeting.

In your sentence, sürdürdük works well because the subject is actively keeping the project going.

The sentence follows a very natural Turkish pattern:

• Projeyi = object
• aylardır = time expression
• aynı tempoda = manner
• sürdürdük = verb

Turkish usually puts the verb at the end, and the material before it often appears in the order of:

object + time + manner/place + verb

So this sentence is very normal and idiomatic.

You could move some parts around for emphasis, but the given order sounds smooth and neutral.

Artık here means now, by now, at this point, or anymore depending on context.

In this sentence, it gives the idea that after all that work over time, the situation has reached a new stage:

• artık sadece ince ayar kaldı = now only fine-tuning remains

So artık signals a shift: we have done the main work, and at this stage only the final adjustments are left.

Literally, ince ayar means fine adjustment or delicate tuning.

Very naturally in English, it is often:

• fine-tuning
• final adjustments

It is used for things like:

• machines
• plans
• systems
• presentations
• projects

In this sentence, ince ayar kaldı means the big work is done and only small refinements remain.

Because kalmak has several common meanings, including:

• to stay
• to remain
• to be left

Here it clearly means to remain / to be left.

So:

• sadece ince ayar kaldı = only fine-tuning remained / is left

In Turkish, this use of kalmak is extremely common:

• Biraz iş kaldı. = A little work is left.
• Sadece iki gün kaldı. = Only two days are left.

So in your sentence, kaldı does not mean someone physically stayed somewhere; it means something remains to be done.

Because ince ayar is being used as a mass/collective idea, much like English fine-tuning.

Turkish often leaves nouns in the singular when talking about an uncounted category or general activity. So:

• ince ayar kaldı = fine-tuning remains
• son rötuşlar kaldı = the final touch-ups remain

Both are possible in Turkish, but they sound slightly different:

• ince ayar kaldı feels more like a general final stage
• ince ayarlar kaldı would sound more like several separate adjustments

The singular works very naturally here.

The semicolon links two closely related clauses:

1. Projeyi aylardır aynı tempoda sürdürdük
2. artık sadece ince ayar kaldı

The second clause is the result or conclusion of the first. In English, you might also write this with:

• a semicolon
• a dash
• a full stop

So the semicolon gives a slightly polished, written feel and shows that the two ideas are tightly connected.

Yes, but the nuance is a little different.

• aylardır = for months now, with a stronger sense of duration up to the present moment
• aylar boyunca = throughout months / for months, often a bit more neutral or descriptive

So:

• Projeyi aylardır aynı tempoda sürdürdük sounds very natural and emphasizes the long ongoing effort.
• Projeyi aylar boyunca aynı tempoda sürdürdük is also possible, but slightly less idiomatic in this exact kind of sentence.

For a learner, aylardır is the more useful phrase to remember here.

It sounds professional, calm, and slightly satisfying.

The tone suggests:

• steady long-term effort
• discipline and consistency
• that the difficult part is mostly finished

So the sentence does not sound emotional or dramatic. It sounds like someone giving a progress update:

We’ve kept the project going at the same pace for months; now only fine-tuning remains.

That makes it very suitable for workplace, project-management, or academic contexts.