1. To write an essay on the largest population group in Afghanistan, begin by conducting some basic research. My go-to site when beginning research is Wikipedia.com. Check out this link:
Then, go to these pages:
According to 2010 data from the US Department of State, the largest ethnic group in Afghanistan is the Pashtun (including Kuchis), comprising 42% of Afghans.1 The Tajiks are the second largest ethnic group, at 27% of the population, followed by the Hazaras (9%), Uzbeks(9%), Aimaq (4%), Turkmen (3%), Baluch (2%) - operartionspaix.net
If your research supports the statistic that Pashtun is the largest people group in Afghanistan, then develop your essay on that ethnic group—consider their origins, culture, traditions, religion, family structure, etc.
Keep in mind that an essay must include an introduction, body paragraphs, and a conclusion. See: http://grammar.ccc.commnet.edu/grammar/five_par.htm"