When I'm to pay for the food I have had at a restaurant, I have to pay for the amount or number of things I have eaten. So how to talk about the amount of "chicken" or numbers of "chickens" I had?
Hi, Ahmed—As Lucas's reply indicates, when you pay for things you have eaten at a restaurant, you pay for what you have had off the restaurant's menu. Maybe you had a dish made with chicken (noncount) or a number of dishes made with chicken. Maybe the restaurant allows you to purchase individual pieces of chicken. In that case, you can talk about how many pieces of chicken you have had. Maybe the restaurant offers buckets of chicken, drumsticks, breasts of chicken. There are any number of ways you could talk about how much chicken you ate at a restaurant, and the language you use will be determined by how the restaurant speaks about the varieties of chicken cuisine it offers. Below is a menu from KFC, an immensely popular fast-food chicken chain in the U.S., at which I have not eaten for many, many years, having been vegetarian for thirty years.
To pay for things on that menu, you tell the cashier what you want.