Learn Farsi: خیابان شلوغ است اما کوچه خلوت است. - The street is crowded, but the alley is quiet.

Yes! Both ammâ and vali mean "but" and are used to connect contrasting ideas. They are almost always interchangeable in Farsi, so saying khiyâbân shologh ast vali kuche khalvat ast is perfectly correct.

Does khalvat mean "quiet" as in "making no noise"?

Not exactly. While it translates to "quiet" here, khalvat specifically refers to a place being uncrowded or empty of people and traffic. If you want to say a place is completely silent, you would use the word sâket. In this sentence, khalvat acts as the direct opposite of shologh (crowded).

Why does the verb ast appear twice here?

The word ammâ joins two complete, independent sentences together. The first is khiyâbân shologh ast (the street is crowded) and the second is kuche khalvat ast (the alley is quiet). Because each part is a full thought, each keeps its own verb at the end. In casual speech, the second ast is sometimes dropped, but it is standard to keep it in writing.

What is the difference between khiyâbân and kuche?

Khiyâbân refers to a main street, road, or avenue that is typically wider and carries city traffic. Kuche refers to a smaller residential side street, lane, or alleyway, which are very common in Iranian cities and naturally much less busy.