Are there a diference between "He did not eat today" and "He has not eaten today." ????
To ask for things that started the moment you were born till now, use the present perfect; when you mention when the action happened, use simple past.
— "HAVE you ever EATEN Thai food?" (Meaning your whole life)
— "Sure, I tried it just last week..." (now you have the moment when the action happened -- last week).
You also use the present perfect fot things that have been happening for the past few days or something that has just happened:
- "I haven't been well lately" (past few days)
- "I have just bought my new apartment" (just happened).
You can't say " I haven't gone to the movies last Saturday", but "I didn't go..." (specific time)...
This is the reason why I would use simple past in Duolingo's example...