Ben dün gece kitap okurken kardeşim odasında piyano çalıyordu; o melodi beni sakinleştiriyordu.

Last night, while I was reading a book, my sibling was playing the piano in his room; that melody was calming me.

Breakdown of Ben dün gece kitap okurken kardeşim odasında piyano çalıyordu; o melodi beni sakinleştiriyordu.

• ben: I
• benim: my
• kitap: the book
• okumak: to read

Questions & Answers about Ben dün gece kitap okurken kardeşim odasında piyano çalıyordu; o melodi beni sakinleştiriyordu.

Why is Ben included at the beginning of the sentence? Could we drop it?

In Turkish the subject pronoun is usually optional because the verb ending already shows who is acting. Ben (I) is added here for emphasis or clarity—perhaps to contrast your action with your brother’s. You can drop it without changing the meaning:
• Dün gece kitap okurken…

What does the -ken suffix in okurken do?

The suffix -ken attaches to a verb to mean “while …ing.” Here okur- is the present stem of okumak (to read), so okurken = “while reading.” It introduces a simultaneous action with the main clause.

Why is çalıyordu used instead of çalıyor or çalacaktı?

Çalıyordu is the past continuous form (“was playing”), built from the root çal- + progressive -ıyor + past -du.
• çalıyor = “is playing” (present continuous)
• çalacaktı = “was going to play” (future-in-the-past)
We use çalıyordu because the brother’s piano playing was ongoing at that past moment (“while I was reading”).

In kardeşim odasında, why do we say odasında and not just odada? How do we form that possessor + locative?