Learn Farsi: به خاطر تمیزی این هتل، همه‌ی مسافرها آن را انتخاب می‌کنند. - Because of the cleanliness of this hotel, all the travelers choose it.

It comes from the adjective تمیز (clean). By adding the suffix ی (i), it turns into the abstract noun تمیزی (cleanliness). This perfectly matches the current lesson's rule for creating abstract nouns out of adjectives.

How do we link تمیزی to این هتل when speaking?

We use the grammatical connector called the ezafe. Because تمیزی ends in the long vowel sound i, the ezafe is pronounced as a ye sound. So you will hear tamizi-ye in hotel (the cleanliness of this hotel).

How does the phrase به خاطر connect to the rest of the sentence?

The phrase به خاطر (because of) must be followed by an ezafe to connect it to the noun that follows it. Here, it connects to تمیزی, so it is pronounced be khâter-e tamizi.

Why is there an extra ی on the word همه (all)?

The word همه acts as a quantifier for مسافرها (travelers). To link them, we need an ezafe. Since همه ends in a silent e sound, Farsi requires us to write an explicit ی to carry the ye ezafe sound, making it همه‌ی مسافرها.