Ağabeyim damatlık için açık renk bir gömlek arıyor, ama babam koyu rengin daha uygun olduğunu söylüyor.

Ağabeyim means my older brother.

It breaks down like this:

• ağabey = older brother
• -im = my

So Turkish often expresses possession with a suffix on the noun, rather than only with a separate word like my.

You could also say benim ağabeyim, but benim is often left out because -im already shows the meaning.

Also, in everyday speech, ağabey is very often shortened to abi.

Because Turkish commonly uses possessive suffixes.

Here:

• ağabey-im = my older brother
• baba-m = my father

The suffix changes depending on the noun:

• -im / -ım / -um / -üm
• sometimes just -m after a vowel, as in baba-m

So English uses a separate word (my), but Turkish often attaches that meaning directly to the noun.

İçin means for.

Damatlık comes from damat meaning groom. In context, damatlık usually means something like:

• the groom’s suit
• wedding suit
• tuxedo/groom’s outfit

So damatlık için means for the groom’s suit/outfit or to go with the wedding outfit.

In Turkish, adjectives normally come before the noun, and bir often comes right before the noun too.

So:

• açık renk = light-colored / light color
• bir gömlek = a shirt

Together:

• açık renk bir gömlek = a light-colored shirt

This word order is very natural in Turkish.

You may also see açık renkli bir gömlek. That is also correct.

• açık renk = light color
• açık renkli = light-colored

Both work, but the version in the sentence is very natural.

Because bir gömlek is an indefinite direct object.

In Turkish:

• indefinite object: usually no accusative
• definite/specific object: usually takes accusative

So:

• bir gömlek arıyor = he is looking for a shirt
• gömleği arıyor = he is looking for the shirt / a specific shirt

That is why gömlek stays bare here.

Arıyor comes from aramak.

Here it means is looking for.

It uses the -yor form, which is commonly taught as the present continuous:

• arıyor = is looking for / is searching for

So:

• Ağabeyim ... gömlek arıyor = My older brother is looking for a shirt

Note that aramak can also mean to call in other contexts, but here it clearly means to look for, because the object is gömlek.

This is a common Turkish sound change.

The noun is renk = color.
When certain suffixes are added, the final consonant can soften:

• renk → reng-

So:

• renk + -in becomes rengin

This kind of consonant change happens with some words ending in p, ç, t, k.

So rengin is the expected form here.

Because this is part of a subordinate clause:
koyu rengin daha uygun olduğunu

This whole section means something like:

• that the dark color is more suitable

In this kind of structure, the subject of the embedded clause often takes the genitive ending:

• koyu renk → koyu rengin

So although it may look like of the dark color, its real function here is the subject of the idea being reported.

Daha uygun means more suitable.

• uygun = suitable, appropriate
• daha = more

So Turkish forms many comparatives with daha:

• daha güzel = more beautiful
• daha iyi = better
• daha uygun = more suitable

In this sentence, the comparison is implied: the father thinks a dark color is more suitable than a light one.

This is a very important Turkish pattern.

söylüyor means says.

What does he say?
He says that it is more suitable.

Turkish often expresses that-clauses by turning them into a noun-like structure.

So:

• uygun = suitable
• olduğunu = that it is / its being

Together:

• daha uygun olduğunu söylüyor = says that it is more suitable

Why is olmak used? Because uygun is an adjective. Turkish often uses olmak inside these embedded structures when the predicate is a noun or adjective.

So this part is very close to:

• He says that the dark color is more suitable.

Yes. It comes from olmak and contains several pieces.

A simplified breakdown is:

• ol- = be, become
• -duk / -dık / -dik / -dük type nominalizing element
• -u = possessive marker used in this clause structure
• -nu = accusative after that

In this sentence, olduğunu is part of a noun-like clause that functions as the object of söylüyor.

So:

• koyu rengin daha uygun olduğunu = that the dark color is more suitable

You do not need to produce the full analysis every time, but it is useful to recognize -dığını / -diğini / -duğunu / -düğünü as a very common pattern after verbs like:

• söylemek
• bilmek
• duymak
• görmek

Because Turkish is usually an SOV language:

• Subject – Object – Verb

So:

• Ağabeyim ... gömlek arıyor
• Babam ... söylüyor

Also, in the second clause, the whole reported idea comes before söylüyor:

• koyu rengin daha uygun olduğunu = the thing being said
• söylüyor = says

This is very normal Turkish word order.

Yes, but it would become direct speech instead of this indirect structure.

For example:

• Babam, koyu renk daha uygun, diyor.

That is more like:

• My father says, dark color is more suitable.

The original sentence is a smoother, more standard indirect statement:

• Babam koyu rengin daha uygun olduğunu söylüyor.
• My father says that the dark color is more suitable.

So both are possible, but the version in the sentence is more grammatical and natural for reported speech.