Learn Turkish: Müdür yeni projeden bahsetti. - The manager talked about the new project.

In English, we use the preposition "about" to introduce a topic of conversation. However, in Turkish, the verb bahsetmek (to talk about / to mention) requires its object to take the ablative case (-dan/-den), which usually translates to "from". You can think of the Turkish logic as bringing up information "from" a topic.

I know etmek is a helper verb that is usually written as a separate word. Why is bahsetti written all together as a single word?

Bahsetmek is formed by combining the noun bahis (topic/mention) and the helper verb etmek (to do). When they combine, the letter 'i' in bahis drops out to make pronunciation easier. In Turkish, whenever a compound verb loses a vowel like this, the two parts must be written together as one word.

Why is the past tense suffix on bahsetti spelled with a 't' (-ti) instead of a 'd' (-di)?

This is due to consonant mutation (often remembered by the phrase Fıstıkçı Şahap). The verb root bahset ends in 't', which is a hard, voiceless consonant. When a suffix starting with 'd' (like the past tense -di) is added right after it, the 'd' hardens into a 't' to match, becoming -ti.

There is no word for "the" before müdür. How do we know it means "the manager" and not "a manager"?