why most south-asian countries end with a 'Stan' like Pakistan,Afghanistan,Uzbekistan,Tajikistan,Turkmenistan?

Answer 1

The suffix –stan is Persian for ‘place of/land of’ and -sthan is related Sanskrit suffix with the same meaning.

They appear in the names of many countries and regions, especially in Central Asia and Indian subcontinent.

Those countries are:
Uzbekistan, Kazakhstan, Kyrgyzstan (previously Kirghizia), Turkmenistan (previously Turkmenia), Tajikistan, Afghanistan, Pakistan.
Also Dagestan (autonomic republic in Caucasus), and Tatarstan (autonomic republic in Russian Federation). But those are not South Asian countries.

However, if you would decide to look up information in Wikipedia, you'll find even more information about countries and places ending with -stan.

Answer 2

The word "stan" simply means land of. Afghanistan was the "land of the Afghan people" Uzbekistan was the "land of the Uzbek people" and Pakistan was the "land of those who were pure"

Answer 3

'Stan' is an ancient Persian/Farsi word meaning Country, land or Place.
All of the 'Stans' have Persian or Turkic origins.

Answer 4

stan means place, so pakistan is the place of paki or pure, afghanistan means place of afghans and so on