Göğsümde hafif bir ağrı olunca biraz oturup dinlendim.

Göğsümde breaks down like this:

• göğüs = chest
• -üm = my
• -de = in / on / at

So the full meaning is in my chest or on my chest, depending on context.

The reason it becomes göğsümde instead of göğüsümde is that some Turkish nouns drop a vowel when a suffix is added. This happens in a number of body-part words.

For example:

• göğüs → göğsüm = my chest
• ağız → ağzım = my mouth
• burun → burnum = my nose

So göğsümde is the normal correct form.

The suffix -de / -da is the locative suffix, which usually means in, on, at.

Here:

• göğsümde = in my chest

In this sentence, it tells you where the pain is located.

A few similar examples:

• kolumda ağrı var = there is pain in my arm
• başımda baskı var = there is pressure in my head
• sırtımda ağrı var = there is pain in my back

So göğsümde gives the physical location of the symptom.

Bir here works like a / an in English.

• hafif bir ağrı = a slight pain

You can sometimes omit bir in Turkish, but with a phrase like this, hafif bir ağrı sounds very natural and complete.

Compare:

• hafif bir ağrı = a slight pain
• şiddetli bir ağrı = a severe pain

Without bir, the phrase can sound more general or more compressed, almost like a label rather than a full everyday expression.

So hafif bir ağrı is the normal everyday way to say a slight pain.

Olunca comes from the verb olmak, which often means to be, to become, or to happen.

Here:

• ağrı olunca = when there was pain / when a pain occurred

This is a very common Turkish pattern. Turkish often uses olmak to express that a condition or situation appears or happens.

So:

• hafif bir ağrı olunca literally means something like when a slight pain happened/occurred

In natural English, you would usually translate it more smoothly as:

• when I felt a slight pain in my chest
• when there was a slight pain in my chest

The suffix -ınca / -ince / -unca / -ünce is a converb ending that often means:

• when
• once
• sometimes since / because, depending on context

So:

• olunca = when it happened / when there was

In this sentence, it introduces the circumstance before the main action:

• Göğsümde hafif bir ağrı olunca = When there was a slight pain in my chest...
• ...biraz oturup dinlendim = ...I sat down and rested a little.

So the whole idea is: When that happened, I did this.

Yes, it can.

In many Turkish sentences, -ınca / -ince is mainly temporal (when), but it can also carry a light cause-and-result feeling.

So this sentence can suggest both:

• when I felt a slight pain in my chest, I sat down and rested
• since I felt a slight pain in my chest, I sat down and rested

English usually chooses one clear option, but Turkish often lets both ideas coexist naturally.

Oturup comes from:

• oturmak = to sit
• -up / -ip / -ıp / -üp = a linking converb suffix

So oturup dinlendim means:

• I sat down and rested
• more literally: having sat down, I rested

This -ip/-up form links two actions with the same subject. It is very common in Turkish.

Examples:

• eve gidip yattım = I went home and lay down
• çay yapıp içtim = I made tea and drank it
• oturup dinlendim = I sat down and rested

It often feels like and, but with a smoother, more connected sense than just listing two separate verbs.

Because these are two completely different verbs:

• dinlenmek = to rest
• dinlemek = to listen

So:

• dinlendim = I rested
• dinledim = I listened

The -n in dinlenmek is part of the verb itself and changes the meaning.

A useful comparison:

• müzik dinledim = I listened to music
• biraz dinlendim = I rested a little

So in this sentence, dinlendim is exactly the right form.

Dinlendim is in the simple past tense.

Breakdown:

• dinlen- = rest
• -di = past tense
• -m = I

So:

• dinlendim = I rested

Notice that in this sentence, the tense is shown only on the final finite verb:

• oturup is not marked for tense
• dinlendim carries the past meaning for the whole main action

This is very normal in Turkish.

Because Turkish usually does not need subject pronouns when the verb already shows the person.

Here:

• dinlendim already means I rested

The -m ending tells you the subject is I.

So ben is unnecessary unless you want emphasis or contrast.

Compare:

• dinlendim = I rested
• ben dinlendim = I rested (with extra emphasis)

In ordinary sentences, Turkish often leaves out ben, sen, o, etc. when the verb makes the subject clear.

Biraz means a little or for a bit.

In this sentence, it most naturally modifies the resting action:

• biraz oturup dinlendim = I sat down and rested a little / for a bit

Even though it comes before oturup, its effect is really on the whole action sequence.

You could think of it as:

• I sat down and rested for a short time

Turkish often places adverbs like biraz before a verb chain like this.

Turkish word order is flexible, but this sentence follows a very natural information flow:

• Göğsümde = location first
• hafif bir ağrı = what the problem was
• olunca = when that happened
• biraz oturup dinlendim = what I did next

So the structure is roughly:

[In my chest] [a slight pain] [when it happened], [I sat down and rested a little].

Putting Göğsümde first helps set the scene immediately.

Turkish often puts background information before the main action, especially in sentences with -ınca/-ince.

Yes. Turkish has several natural ways to express a similar idea.

For example:

• Göğsüm ağrıyınca biraz oturup dinlendim.
  = When my chest started hurting, I sat down and rested a little.

• Göğsümde hafif bir ağrı hissedince biraz oturup dinlendim.
  = When I felt a slight pain in my chest, I sat down and rested a little.

The original sentence uses ağrı olunca, which focuses on the occurrence of the pain. Other versions may focus more on feeling it or on the chest hurting directly.

All of these are natural, but they are slightly different in nuance.

It can suggest either, depending on how literally you want to read it.

Most directly:

• oturup dinlendim = I sat down and rested

But in natural English, it may be translated more smoothly as:

• I sat down to rest
• I sat for a while and rested

That is because the -up/-ip form often connects actions that belong together as one practical sequence.

So the Turkish is slightly more explicit than English, but the overall idea is very natural in both languages.