Learn Farsi: ساخت‌وساز در این محله خیلی زیاد است. - There is a lot of construction in this neighborhood.

This is a coordinate compound noun that expresses an abstract action, in this case construction. It is formed by taking the past stem of ساختن (sâxtan - to build), which is ساخت (sâxt), and its present stem, ساز (sâz), and linking them with و. So literally, it translates to built-and-build.

How do I pronounce the و in the middle of ساخت‌وساز?

In compound nouns like this, the و is not pronounced as the full word va. Instead, it acts as a bridge pronounced as a quick -o-. The entire word flows together and is pronounced sâxt-o-sâz.

Why does the sentence use خیلی زیاد (xeili ziyâd) instead of just using خیلی?

While خیلی (xeili) can mean a lot on its own, it often acts as an intensifier meaning very. By pairing it with زیاد (ziyâd, meaning much or many), you get a phrase that unambiguously means a great amount. In Farsi, you literally say construction is very much to express there is a lot of construction.

Is محله (mahalle) related to the word محل (mahal)?

Yes, they are closely related. محل (mahal) generally means place or location. By adding the ه suffix at the end, it becomes محله (mahalle), which specifically means a neighborhood or residential district within a city.