✔ 最佳答案
There are a lot of Nepalis (no need to use “peoples” because you already used Nepalis. Moreover for people we do not need to add an “s” unless you are talking about different races of people) pass through my workplace and they (no “was” because we are using present tense) sometime buy food (changed from rice to food because I believe you do not mean they only buy rice from you) from our place. One day I wanted to ask them in English: When did you have your last meal? But I didn't know (after the verb “did” we do not need to change the tense) how to say it (we can always speak, but to “say it” is different. Moreover you should not use a “?” here. Just a full stop is okay). My brain went blank. At that (you are talking something happened during “that” time, so change from “this” to “that”) time, I wanted to cry. Then another day I heard my colleague spoke in simple English. And I asked myself, why I didn't know how to say it. I was very upset. I am asking myself again on whether or not I am studying English course now! (Again, this is not really a question, so no need to use “?”)
Note:
1. Nepalese is another name to call the people from Nepal , same as Nepalis. However the official name from the Nepal tourism is Nepalis.
2. Since you talked about many Nepalis passing through the place you work sometimes, so please use present tense on the first part of your passage.