Ölü balığı sudan çıkardık.

Because balığı has the accusative ending. In Turkish, a specific/definite direct object usually takes this ending.

• balık = fish
• balığı = the fish / a specific fish (as the object)

So in this sentence, the speaker is talking about a particular dead fish, not just fish in general.

Also notice the spelling change:

• balık + ı → balığı

The final k changes to ğ when a vowel-initial suffix is added. This is a very common sound change in Turkish.

Ölü is an adjective here, meaning dead. It describes balığı.

So:

• ölü balık = dead fish
• ölü balığı = the dead fish (as a specific object)

In Turkish, adjectives come before the noun, just like in English:

• dead fish
• ölü balık

Sudan means from the water or out of the water.

It is made from:

• su = water
• -dan / -den = from

So:

• su → sudan = from the water

This is the ablative case, which often expresses movement away from something.

In this sentence, it shows where the fish was taken out of.

This is a very important difference.

• çıkmak = to go out / come out
• çıkarmak = to take out / remove / cause to come out

So:

• çıktık = we went out
• çıkardık = we took out

In this sentence, we are doing something to the fish, so Turkish uses the transitive verb çıkarmak.

A simple way to think about it:

• balık çıktı = the fish came out
• balığı çıkardık = we took the fish out

Turkish verbs often include the subject inside the verb ending, so a separate word for we is usually unnecessary.

çıkardık can be broken down roughly like this:

• çıkar- = take out
• -dı- = past tense
• -k = we

So çıkardık means we took out.

That is why the sentence does not need a separate biz.

Turkish does not normally have a separate word like English the.

Instead, definiteness is often shown in other ways, especially with the accusative case for direct objects.

So in this sentence:

• balığı strongly suggests the fish or that fish
• sudan can mean from the water, depending on context

Turkish often lets context and case endings do the job that English articles do.

The sentence follows a very typical Turkish pattern:

Object + place/source + verb

• Ölü balığı = the dead fish
• sudan = from the water
• çıkardık = we took out

Turkish usually puts the verb at the end.

So this sentence is very natural Turkish word order.

Yes, you could say:

Biz ölü balığı sudan çıkardık.

That would still mean We took the dead fish out of the water.

But Turkish often leaves out subject pronouns when they are already clear from the verb ending. Since -k already shows we, biz is usually unnecessary unless you want emphasis or contrast.

For example, biz might be added if you want to stress:

• We took it out, not someone else.

This is a common consonant change in Turkish.

Some words ending in k soften when a vowel-initial suffix is added:

• balık
  • -ı → balığı

This is called consonant softening.

Other common examples:

• köpek → köpeği
• çocuk → çocuğu

So balığı is the expected form.

Only the noun gets the case ending.

So:

• ölü = adjective
• balığı = noun with accusative ending

Turkish adjectives do not change for case, number, or gender. They stay the same.

That means:

• ölü balık
• ölü balığı
• ölü balıktan

The adjective ölü stays unchanged each time.

Yes, depending on context, English translation can vary a little.

Sudan literally means from water / from the water. In natural English, out of the water is often the best translation here.

Turkish does not force the same article choices as English, so the exact English wording depends on context:

• from the water
• out of the water
• sometimes just from water

But in most situations, We took the dead fish out of the water is the most natural English translation.