"Who is the fisherman?"
Translation:Ai là ngư dân?
To translate a question from English into Vietnamese, the easiest way is to translate it word-by-word.
What = Cái gì (a non-living thing)/ Con gì (a living thing). Which = Cái nào/ con nào. Who and Whom = Ai. Why = Tại sao. How = Làm sao. When = Khi nào.
Your sentence is also correct and by far is more common in use. All interrogatives above can stand at the end of a question and make a slightly different meaning in terms of the point of departure of the message, but I think the grammatical point should be given in other lessons. Too many transformations of sentence structures would put the learners in difficulty.
In English, "the" is a definite article. An entity modified by 'the' is either in the discourse, or in our general knowledge of the world that identifies it for us.
In Vietnamese, the equivalence to 'the' is the post noun complements "đó", "đấy", "này", "nọ" (as in "cái đó", "cái đấy", "cái này", "cái nọ" = "the thing"). Note that, the post complements encompass the grammatical use of both the article 'the' and determiners 'this', 'that', 'these', 'those' and sometimes the pronoun 'it'. We also don't use any post complements to call an entity of general knowledge or an entity that is one of a kind for the first time it happens in the discourse, for instances: The Eiffel Tower = Tháp Ép-phen, the USA = nước Mỹ, the President = Tổng thống, etc. To refer to the entity again, we sometimes use post complements, but they are optional.
To sum up, in my opinion, the translation of 'Who is the fisherman?' into Vietnamese is: "Ai là ngư dân đó/ đấy/ này/ nọ" because it suggests that the speaker and the listener have known about the specific entity before the sentence takes place.
Your translation of 'Who is a fisherman?' is correct in accordance with the rules of thumb in translation. But normally, the Vietnamese omit "một" and go with "Ai là ngư dân?"
Can anyone explain what is the difference between “ai là ngư dân” án “ngư dân là ai”? Base on my knowledge on Chinese language, which has a similar question sentence structure, putting the “who” in front focuses the question on “who” and therefore is better translated as “who is A fisherman” while putting “fisherman” in front focuses the question on the fisherman as in “who is THE fisherman” Can anyone tell me if the same is applied to Vietnamese?