Yanlış kişiye mesaj atınca mahcup oldum ve hemen özür diledim.

Yanlış kişiye means to the wrong person.

The ending -ye is the dative case, which often corresponds to to in English.

• kişi = person
• kişiye = to the person
• yanlış kişiye = to the wrong person

The y is a buffer consonant. Since kişi ends in a vowel and the dative ending also begins with a vowel, Turkish inserts y:

• kişi + e → kişiye

So in this sentence, yanlış kişiye shows who received the message.

Yes, atmak very often means to throw, but in modern Turkish it is also commonly used in expressions like:

• mesaj atmak = to send a message / text
• mail atmak = to send an email
• DM atmak = to send a DM

So mesaj atmak is a very natural everyday expression, especially in casual speech.

It is one of those verb combinations that learners simply have to get used to, much like English uses make a call instead of do a call.

Atınca comes from:

• at- = send / throw
• -ınca / -ince = when, once, after

So mesaj atınca means:

• when I sent the message
• once I sent the message
• after sending the message

In this sentence, Yanlış kişiye mesaj atınca... means something like:

• When I sent a message to the wrong person...
• After I sent a message to the wrong person...

The exact English translation can vary a little depending on context, but the basic idea is that one event happened and then the next followed.

This is a very common question for English speakers.

In Turkish, subordinate forms like -ınca often do not show the person explicitly. The subject is usually understood from context, especially from the main verb.

Here, the main verbs are:

• oldum = I became / I felt
• diledim = I apologized

Because both main verbs are first person singular, we naturally understand atınca as when I sent.

So the sentence is interpreted as:

• When I sent a message to the wrong person, I felt embarrassed and immediately apologized.

Turkish often leaves this kind of subject information to context.

Mahcup oldum means I became embarrassed or I ended up embarrassed.

This uses:

• mahcup = embarrassed / ashamed
• olmak = to become / to be

So:

• mahcup oldum = I became embarrassed / I felt embarrassed

Compare:

• mahcupum = I am embarrassed
• mahcuptum = I was embarrassed
• mahcup oldum = I became embarrassed / I felt embarrassed

In this sentence, oldum fits well because it describes the emotional reaction that happened after sending the message.

They are similar, but not identical.

• mahcup olmak often suggests feeling embarrassed, awkward, or a bit ashamed in a social situation.
• utanmak / utandım means to be ashamed / to feel embarrassed, and can sometimes sound a bit more direct or emotionally strong depending on context.

In this sentence, mahcup oldum sounds very natural because sending a message to the wrong person is the kind of situation that causes social embarrassment.

So:

• mahcup oldum = I felt embarrassed / awkward
• utandım = I got embarrassed / I felt ashamed

Both can work in many contexts, but mahcup often fits polite, mildly uncomfortable situations very well.

Özür dilemek is the standard Turkish expression for to apologize.

• özür = apology / excuse
• dilemek = to wish, request, express

But as a fixed expression, özür dilemek simply means to apologize.

So:

• özür diledim = I apologized

This is a collocation, so learners should memorize it as a whole phrase.

You generally do not say things like:

• özür söyledim for I apologized

Instead, use:

• özür dilemek
• sometimes also kusura bakma(k) in informal contexts, depending on meaning

Both are in the simple past tense with -di.

• oldum = I became / I was
• diledim = I apologized

Breakdown:

• ol-du-m

  • ol- = become / be
  • -du = past
  • -m = I

• dile-di-m

  • dile- = ask/wish, here part of özür dilemek
  • -di = past
  • -m = I

So the sentence narrates completed past events.

Turkish often drops subject pronouns when the verb ending already makes the subject clear.

Here:

• oldum = I became
• diledim = I apologized

Because the -m ending already tells us the subject is I, adding ben is usually unnecessary.

If you say Ben ... oldum ve ... diledim, it is not wrong, but it would add emphasis, like:

• I was the one who felt embarrassed and apologized.

In ordinary speech, leaving out ben is more natural.

Yes, hemen can move, but the current position is very natural.

• hemen = immediately / right away

In the sentence:

• mahcup oldum ve hemen özür diledim
• = I felt embarrassed and immediately apologized

This placement makes hemen modify özür diledim clearly.

Other possible orders are also grammatical, for example:

• Yanlış kişiye mesaj atınca hemen mahcup oldum ve özür diledim.
• Yanlış kişiye mesaj atınca mahcup oldum, özrü de hemen diledim.

But the original sentence is smooth and natural.

Good question. In Turkish, the accusative often marks a specific, definite direct object.

Here we have:

• yanlış kişiye mesaj atınca

This is a common, general way to say when I sent a message to the wrong person.

If you said mesajı attım/atınca, it could make the message sound more specific, like:

• the message
• a particular message already known in context

So:

• mesaj atmak = to send a message
• mesajı atmak = to send the message

In many everyday sentences, the unmarked form sounds more neutral and natural.

Yes, absolutely. That is a very natural English translation.

The Turkish sentence does not literally contain a separate word for accidentally, but the idea is strongly implied by the situation:

• Yanlış kişiye mesaj atınca = when I sent a message to the wrong person

In English, adding accidentally often makes the translation sound more natural, because people usually do not message the wrong person on purpose.

So both of these are good:

• When I sent a message to the wrong person, I felt embarrassed and immediately apologized.
• When I accidentally texted the wrong person, I felt embarrassed and immediately apologized.

It is mostly neutral everyday Turkish.

A few notes:

• mesaj atmak is common and slightly conversational
• mahcup oldum sounds natural and polite
• özür diledim is standard and appropriate in both casual and more polite situations

So the whole sentence works well in normal spoken or written Turkish. It is not slangy, but it is also not overly formal.