Ben bugün öğleden sonra kütüphanede ders çalışacağım.

Yes. Turkish often drops subject pronouns when they are already clear from the verb ending.

So:

• Ben bugün öğleden sonra kütüphanede ders çalışacağım.
• Bugün öğleden sonra kütüphanede ders çalışacağım.

both mean I will study at the library this afternoon.

The -acağım ending already shows I.
Using ben adds emphasis, contrast, or clarity, like:

• I will study, not someone else.
• As for me, I’ll study this afternoon.

So ben is grammatical, but often optional.

It means this afternoon.

Breakdown:

• bugün = today
• öğleden sonra = literally after noon

Together, bugün öğleden sonra means today in the afternoon, which natural English usually translates as this afternoon.

A learner may expect one single Turkish word for afternoon, but Turkish commonly uses the expression öğleden sonra.

Because it is a fixed expression made of separate parts:

• öğle = noon
• öğleden = from noon / after noon
  
  • this includes the ablative ending -den
• sonra = after

So the phrase literally comes from the idea of after noon. In modern usage, öğleden sonra functions as a time expression meaning in the afternoon / afternoon.

It is normally written as two words.

Kütüphanede means in the library or at the library.

Breakdown:

• kütüphane = library
• -de = location ending, often called the locative suffix

So:

• kütüphane = library
• kütüphanede = in/at the library

This suffix is used when something happens in a place:

• evde = at home
• okulda = at school
• masada = on the table
• kütüphanede = in the library

In English we use prepositions like in, at, or on.
In Turkish, this idea is often shown with a suffix attached directly to the noun.

Because of vowel harmony.

The locative suffix has forms like:

• -da
• -de
• sometimes -ta / -te after certain consonants

The choice depends on the last vowel and sometimes the last consonant of the noun.

In kütüphane, the last vowel is e, a front vowel, so the suffix becomes -de:

• kütüphane + de → kütüphanede

Compare:

• okulda = at school
• evde = at home
• parkta = in the park
• şehirde = in the city

So -de is the correct vowel-harmony form here.

This is a very common question.

Çalışmak can mean to work, but with ders it means to study.

• ders = lesson, class, school subject
• ders çalışmak = to study

So in this sentence:

• ders çalışacağım = I will study

This is a very common Turkish expression.
You should learn ders çalışmak as a set phrase.

Compare:

• Çalışıyorum. = I am working.
• Ders çalışıyorum. = I am studying.

So the presence of ders changes the meaning.

Çalışacağım means I will study or I am going to study.

It is built from:

• çalış- = study / work
• -acak / -ecek = future tense
• -ım / -im / -um / -üm = I ending

In this word:

• çalış + acak + ım
• becomes çalışacağım

So the whole form means I will study.

This is the Turkish future tense in the first person singular.

Because of a common sound change in Turkish.

The future suffix is -acak / -ecek.
When a personal ending beginning with a vowel is added after it, the final k often changes to ğ.

So:

• çalışacak + ım
• becomes çalışacağım

This happens very often:

• yapacağım = I will do
• gideceğim = I will go
• bakacağım = I will look
• çalışacağım = I will study

So çalışacağım is the normal correct form.

The sentence is:

• Ben bugün öğleden sonra kütüphanede ders çalışacağım.

A helpful breakdown is:

• Ben = subject
• bugün öğleden sonra = time
• kütüphanede = place
• ders = object-like part of the expression ders çalışmak
• çalışacağım = verb

So the order is roughly:

Subject + Time + Place + Object + Verb

This is a very natural Turkish sentence pattern.

Turkish often puts the main verb at the end.
That is one of the biggest differences from English.

Yes. Turkish word order is flexible, although some orders sound more neutral than others.

The original sentence is very neutral:

• Ben bugün öğleden sonra kütüphanede ders çalışacağım.

But you could also say things like:

• Bugün öğleden sonra kütüphanede ders çalışacağım.
• Kütüphanede bugün öğleden sonra ders çalışacağım.

These versions still mean roughly the same thing, but the focus changes a little.

For example:

• starting with kütüphanede can highlight the place
• starting with bugün öğleden sonra can highlight the time

So the original order is a good standard one for learners, but not the only possible order.

Not in exactly the same way English learners may expect.

In ders çalışmak, ders is part of a fixed expression meaning to study. It often behaves like an object in practice, but it is best for learners to remember the whole phrase as a unit.

Important point:

• ders çalışmak = to study
• not literally just to work a lesson in normal English

Also, ders here has no accusative ending. That is normal in this expression.

So for learning purposes, it is most useful to treat ders çalışmak as a chunk.

Because Turkish usually expresses tense through suffixes, not separate helper words.

In English:

• I will study

In Turkish:

• çalışacağım

The future meaning is built into the verb through the suffix -acak / -ecek plus the personal ending.

So Turkish does not need a separate word like will here.

The Turkish letter ğ is often difficult for English speakers.

In many cases, ğ is not pronounced like a strong consonant. Instead, it often:

• lengthens the vowel before it, or
• creates a smooth glide between vowels

So:

• öğleden
• çalışacağım

do not have a hard g sound like in English go.

Very roughly:

• öğle sounds something like oe-leh with a softened transition
• çalışacağım has a smooth flow around the ağ part, not a hard g

A good habit is: when you see ğ, do not pronounce it like a normal English g.

Both can work.

The Turkish locative -de covers meanings that English often expresses with different prepositions, such as in and at.

So:

• kütüphanede ders çalışacağım can be translated as
  • I’ll study in the library
  • I’ll study at the library

Which English version sounds best depends on context and style.
In many everyday situations, either is fine.

Yes.

The Turkish future form -acak / -ecek can often correspond to both:

• will study
• am going to study

English makes a distinction sometimes, but Turkish often uses the same future form for both.

So çalışacağım can naturally be understood as:

• I will study
• I’m going to study

The context decides which English translation sounds best.

A few very useful points appear in just one sentence:

1. Pronouns can be omitted

   • Ben is optional because -acağım already means I

2. Turkish uses suffixes instead of prepositions in many cases

   • kütüphanede = in/at the library

3. The verb usually comes at the end

   • çalışacağım is final

4. The future tense is built into the verb

   • -acak / -ecek

5. Some meanings are learned as phrases

   • ders çalışmak = to study

So this sentence is a very good example of basic Turkish sentence structure.