Ödevin son tarihi cuma, ama teslim tarihi çevrimiçi sistemde perşembe görünüyor.

Because ödevin has the genitive ending -in, which often means of the homework or the homework’s.

So:

• ödev = homework / assignment
• ödevin = of the homework / the homework’s

In ödevin son tarihi, Turkish is using a possessive structure:

• ödevin = the homework’s
• son tarihi = final date / deadline

Literally, it is something like the homework’s final date.

That -i is the 3rd person possessive suffix, used in this kind of noun phrase.

In Turkish, when you say X’in Y’si (X’s Y), you usually mark both parts:

• possessor gets the genitive
• possessed noun gets a possessive suffix

So:

• ödevin = the homework’s
• son tarihi = its final date

This is a very common Turkish pattern:

• öğrencinin adı = the student’s name
• evin kapısı = the house’s door
• ödevin son tarihi = the homework’s deadline

Because teslim tarihi is a very common noun compound meaning submission date or due date.

Turkish often forms noun compounds like this:

• teslim tarih-i = submission date
• okul müdür-ü = school principal
• yemek masa-sı = dining table

In these compounds, the second noun often takes the same -(s)i ending.

So here:

• teslim = submission / delivery
• tarihi = date (in compound form)
• teslim tarihi = submission date / due date

Even without an explicit possessor, this structure is normal.

Yes and no: in English, yes; in Turkish, no.

Turkish often leaves out the present-tense form of to be in sentences like this.

So:

• Ödevin son tarihi cuma.
• literally: The homework’s deadline Friday.
• natural English: The homework’s deadline is Friday.

The is is understood.

Turkish can add -dır in some contexts, but it is more formal, emphatic, or explanatory:

• Ödevin son tarihi cumadır.

That is grammatical, but less neutral in everyday speech.

Because in Turkish, days of the week and months are normally not capitalized unless they begin a sentence.

So Turkish writes:

• cuma
• perşembe
• ocak
• nisan

This is different from English, where Friday and Thursday are capitalized.

Çevrimiçi sistemde means in the online system or on the online system.

Breakdown:

• çevrimiçi = online
• sistem = system
• sistemde = in/on the system

The ending -de is the locative case, which often means:

• in
• on
• at

So:

• okulda = at school
• evde = at home
• sistemde = in/on the system

In English, on the system may sound more natural, but Turkish uses the locative here.

Here görünüyor means something like:

• appears
• seems
• looks
• shows up as

It comes from görünmek, which means to appear / to be visible / to seem.

So:

• teslim tarihi ... perşembe görünüyor
• literally: the submission date ... appears Thursday
• natural English: the submission date appears as Thursday / looks like Thursday / shows Thursday

In this context, it suggests what the system is displaying.

It does not mean that something is literally seeing something. It is from görünmek (to appear), not görmek (to see).

The -yor form is often called the present continuous, but in Turkish it is used more broadly than English is ...-ing.

Here it gives the idea of a current visible state:

• perşembe görünüyor = it appears/shows as Thursday right now

With verbs like görünmek, -yor is very natural when talking about how something currently looks or appears.

A form like görünür is possible in other contexts, but it would sound more general, formal, or habitual, not as natural here.

The second clause is:

ama teslim tarihi çevrimiçi sistemde perşembe görünüyor

A rough breakdown is:

• ama = but
• teslim tarihi = the submission date
• çevrimiçi sistemde = in the online system
• perşembe = Thursday
• görünüyor = appears / seems

A very literal order would be:

But the submission date in the online system Thursday appears.

That sounds strange in English, but it is normal for Turkish to keep the verb near the end.

Turkish word order is flexible, but this sentence follows a very natural pattern: topic/subject + location + complement + verb

They are close in meaning, but not exactly identical.

• son tarih(i) = final date, deadline, last possible date
• teslim tarih(i) = submission date, due date, hand-in date

In many contexts they may both be translated as deadline, but the nuance is a bit different:

• son tarih emphasizes the last allowable date
• teslim tarihi emphasizes the date of submission

That is why this sentence sounds like it is contrasting two date labels: the actual deadline is Friday, but the system is showing Thursday as the submission date.

Yes. Ama means but, and it is very common in everyday Turkish.

You could also say:

• fakat = but / however
• ancak = but / however

So these are all possible:

• ... cuma, ama ...
• ... cuma, fakat ...
• ... cuma, ancak ...

The difference is mostly style:

• ama = most common and conversational
• fakat = a bit more formal or written
• ancak = can sound more formal or emphatic depending on context

In this sentence, ama sounds perfectly natural.

Because Turkish does not have articles like English the and a/an.

So Turkish often leaves definiteness to be understood from:

• context
• word order
• possessive structures
• case markings

For example:

• ödevin son tarihi is clearly a specific deadline
• çevrimiçi sistemde refers to a specific online system understood from context

So even without the, the sentence naturally means:

• the homework’s deadline
• the online system
• the submission date