O kocasıyla konuştu.

O is the third-person singular pronoun in Turkish. It can mean he, she, or it, depending on context. Turkish does not mark gender in this pronoun.

Here it is capitalized only because it is the first word of the sentence.

Yes. Turkish often drops subject pronouns when the subject is already clear from context.

So Kocasıyla konuştu can also mean He/She talked with his/her husband.

Including O usually adds a little emphasis, contrast, or clarity, such as as for him/her or that person.

Because kocası means his husband / her husband.

The noun koca means husband.
To show possession in Turkish, you add a possessive suffix:

• koca = husband
• kocası = his/her husband

The ending here is the third-person singular possessive suffix -(s)I. Since koca ends in a vowel, the suffix appears with a buffer s:

• koca + sı → kocası

-yla here means with.

It is a suffixed form of ile, which means with. After a vowel, ile often attaches to the previous word and becomes -yla or -yle.

So:

• kocası ile = with his/her husband
• kocasıyla = with his/her husband

Both are correct. The attached form is very common.

Because Turkish is highly suffixing. What English often expresses with separate words, Turkish often expresses by adding endings directly to the noun.

So this word breaks down as:

• koca = husband
• -sı = his/her
• -yla = with

Together:

• kocasıyla = with his/her husband

It can mean either. Turkish does not distinguish his and her in this form.

So kocası can mean:

• her husband
• his husband

Context tells you which one is meant.

In this sentence, people will usually understand it as belonging to the person referred to by O, unless the wider context suggests otherwise. If Turkish wants to be extra clear about his/her own husband, it can use kendi, as in kendi kocasıyla.

That is just how konuşmak commonly works in Turkish.

With konuşmak, the person you are having the conversation with is very often marked by ile / -le / -la / -yle / -yla, which corresponds to with.

So Turkish naturally says something like:

• biriyle konuşmak = to talk with someone

Even if English prefers talk to in many situations, Turkish still commonly uses the equivalent of with here.

Konuştu is the simple past form of konuşmak, which means to talk / to speak.

Breakdown:

• konuş- = talk / speak
• -du / -dı / -di / -dü = past tense suffix, with vowel harmony and sound changes

Because the verb stem ends in the voiceless consonant ş, the d of the past tense becomes t. That is why you get:

• konuştu

So konuştu means talked / spoke.

This is the regular definite past tense, often used for completed events.

Because Turkish normally places the finite verb at the end.

A very neutral Turkish word order is:

• subject + other elements + verb

So:

• O = subject
• kocasıyla = with her/his husband
• konuştu = talked

That makes the sentence structure very natural in Turkish.

Yes, but changing the order usually changes the emphasis, not the basic meaning.

For example, Turkish can move elements earlier in the sentence to highlight them. But the most neutral version is the one you have:

• O kocasıyla konuştu.

That sounds like a straightforward statement with no special emphasis.