Translation:Have your parents ever done it in front of you?
I wrote, "Did your parents ever do it in front of you?" Why is it wrong? It's still past tense.
But the English needs the present perfect tense, not the past tense. Have you ever is not asking about some concrete time in the past.
You are correct for British English, but not for American English. AmE uses the present perfect far less than BrE, and in fact "ever", "already" and "yet" normally take the past simple in AmE.
I found this resource http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv123.shtml which confirms it, I will add it.
Other members of the team have better knowledge of US English but I have only lived in England.
In other sentences we do accept the past simple and if it is not accepted yet I will add it.
I wrote this: "Your parents sometimes did that in front of you?" and it was rejected. Was it because I did not phrase it in the form of a question? I also tried "Did your parents sometimes do that in front of you?" and that didn't fly either. I would say "Have your parents ever done that?" to refer to an action that may have been done only once or perhaps more than once, and "Did they sometimes do that?" to mean that it might have happened more than once. What is the Czech connotation here?
Yes, you should phrase it as a question.
Why "sometimes" in this kind of sentence instead o ever? (note I am an ESL speaker)
But "Have you ever done that..." is certainly accepted.
The Czech connotation is asking whether it has ever happened.