Are there any differences in these two sentences? For example, in what situation we should use the second sentence? or the first sentence?
"Have you ever tried Korean food?"
"Have you ever tried Korean food before?"
Thanks for your help
I think there is a subtle difference. The first sentence could be a general question raised during a general discussion about food, maybe as you are trying to decide what to eat or talking about food preferences.
The second question sounds to me like it would be asked as you are sitting down to a Korean dinner and you want to know if it's your dinner companion's first experience with Korean food. My mind adds an unspoken "now" at the end (Have you tried Korean food before now?) I agree that "ever" is unnecessary in the second question.
That subtle difference may be too subtle to be a concern. You probably could interchange the questions without causing confusion.