Learn Turkish: Müdürün ofisi boştu. - The manager's office was empty.

In Turkish, "was" or "were" isn't a separate word. Instead, it is added as a suffix directly to the end of the noun or adjective. Here, the past tense suffix -tu is attached directly to boş (empty) to mean "was empty".

Why does boş (empty) take -tu instead of the regular past suffix -di?

This happens because of two pronunciation rules. First, boş ends in ş, which is a voiceless consonant (often remembered as the "Fıstıkçı Şahap" rule). This changes the d in -di to a t. Second, because the vowel in boş is o, vowel harmony changes the i to a u. So, -di becomes -tu, giving us boştu (was empty).

What does the -ün in müdürün mean?

The -ün suffix shows possession, similar to the apostrophe-s ('s) in English. It changes müdür (manager) to müdürün (the manager's).

If müdürün already means "the manager's", why is there an -i at the end of ofis?