Kusura bakma, seni duyamadım.

Literally, it is something like don’t look at the fault or don’t see it as a fault.

But as a fixed expression, kusura bakma means things like:

• sorry
• forgive me
• don’t take it the wrong way
• please excuse me

So in this sentence, it works as a natural apology before explaining: Sorry, I couldn’t hear you.

Yes, bakmak usually means to look. But in Turkish, some expressions use verbs in ways that do not translate word-for-word into English.

In kusura bakma, the idea is roughly:

• kusur = fault, defect, blame
• bakmak = to look at, regard
• kusura bakma = don’t regard it as a fault / don’t blame me

So even though bakmak usually means to look, here it is part of a set phrase that simply means sorry or excuse me.

Because kusur takes the dative ending -a here:

• kusur = fault
• kusura = to the fault / at the fault

This is part of the fixed expression kusura bakmak. You do not need to translate the dative too literally in English; it is just the form Turkish uses in this phrase.

So learners should mainly remember:

• kusura bakma = informal sorry / excuse me
• kusura bakmayın = polite/plural sorry / excuse me

Yes. bakma is the singular informal imperative, used with sen.

So:

• Kusura bakma = informal, to one person you are close to
• Kusura bakmayın = polite or plural

If you are speaking to someone older, a stranger, or in a more formal setting, kusura bakmayın is usually better.

Seni means you as the direct object.

• sen = you (subject form)
• seni = you (object form)

In seni duyamadım, you is the thing/person not heard, so Turkish uses the accusative form:

• Ben seni duyamadım. = I couldn’t hear you.

Using sen there would be ungrammatical.

It breaks down like this:

• duy- = hear
• -a- = ability/potential marker
• -ma- = negation
• -dı- = past tense
• -m = I

So:

• duy-a-ma-dı-m
• literally: hear - be able to - not - past - I
• natural meaning: I couldn’t hear

This is a very common Turkish pattern:

• yapamadım = I couldn’t do
• gelemedim = I couldn’t come
• anlayamadım = I couldn’t understand

Grammatically, duyamadım most directly means I couldn’t hear.

That is slightly different from:

• duymadım = I didn’t hear

The difference is:

• duymadım can simply state that the hearing did not happen
• duyamadım suggests inability: maybe it was too noisy, too quiet, unclear, etc.

In real conversation, Kusura bakma, seni duyamadım often feels very natural for Sorry, I didn’t catch what you said or Sorry, I couldn’t hear you.

You can say duymadım, but the meaning shifts a bit.

Compare:

• Seni duymadım. = I didn’t hear you.
• Seni duyamadım. = I couldn’t hear you.

The second one is often more polite or more explanatory, because it implies the problem was with the situation, not with the person. It can sound a bit softer, like I wasn’t able to hear you rather than just I didn’t hear you.

That -a- is part of the ability/potential construction.

With many verbs, Turkish forms can / be able to using a vowel plus bilmek in some contexts, but there is also a shorter fused form with many common verbs. In this sentence:

• duymak = to hear
• duyabilmek = to be able to hear
• duyamamak = to be unable to hear

So duyamadım is the past form of duyamamak.

For learners, it is best to recognize this pattern as a whole:

• anlayamadım = I couldn’t understand
• bulamadım = I couldn’t find
• duyamadım = I couldn’t hear

Turkish often drops subject pronouns when the verb already shows who the subject is.

In duyamadım, the final -m means I. So ben is not necessary.

You could say:

• Ben seni duyamadım.

But it is usually omitted unless you want emphasis or contrast.

So the full logic is:

• (Ben) seni duyamadım. = (I) couldn’t hear you.

Yes. Turkish word order is flexible, although some orders sound more natural in certain contexts.

The given sentence:

• Kusura bakma, seni duyamadım.

is very natural.

You could also hear:

• Seni duyamadım, kusura bakma.
• Kusura bakma, duyamadım seni.
  This is possible, but less neutral and more marked.

The most neutral structure for the second clause is seni duyamadım.

Usually özür dilerim sounds more formal or more serious.

Roughly:

• kusura bakma = sorry / excuse me / my bad
• özür dilerim = I apologize

In this sentence, kusura bakma is a very natural everyday choice, especially if you are just saying you did not hear someone.

If the situation were more formal, you might say:

• Kusura bakmayın, sizi duyamadım.
• Özür dilerim, sizi duyamadım.

Because seni is informal singular you, while sizi is polite singular or plural you.

So the sentence matches informal speech all the way through:

• Kusura bakma = informal
• seni = informal singular object

A polite version would be:

• Kusura bakmayın, sizi duyamadım.

That is a very useful pair to learn.

Mostly yes, but in conversation it can also mean I didn’t catch that.

Depending on context, duymak can mean:

• physically hear a sound
• hear what someone said
• receive news/information

In Kusura bakma, seni duyamadım, the most natural reading is: Sorry, I couldn’t hear you / I didn’t catch what you said.