Q:

Is it sin to asking similar question again?

I have asked a question and I got detailed explanation for that question. The knowledge and gist that I got from that answer useful to me to write better questions in SE. How ever I have another question which is some what similar to earlier one. My perception is that the answer for the earlier question helps in general but not in specific. I thought asking about specific question and post that question in ELU. I got again nice and detailed and well explained answer for my second question. I am happy about that. 
How ever one of the honorable user who had high reputation commented upon the answerer "it's a shame you've had to tell all this twice to the same user" by refering the user who answered both of my questions. I realized that user is a bit upset with my question. But I am trying to understand what makes him upset. Definitely the basic points of the answer for the first question are useful. But I feel like require more elaboration to write fully qualified and qualitative questions in ELU for the scenarios which I had specified in question2. At this situation please find my specific question below
(1) If there is a confusion or lack of clarity in order to apply the  knowledge available in ELU or if feel like need more detailed explanation about any specific case then does asking community for explanation isn't right thing to do?
(2) As a non native English speaker inspite of my best efforts some times I cacce difficulties to absorb the knowledge from the articles written in English language and some times takesmore than necessary effort to digest it. Also some times  it is difficult to apply that knowledge every where and encounter difficulties. In such cases does asking question about those difficulties in ELU is wrong?
(3) "it's a shame you've had to tell all this twice to the same user". I might be wrong, but these comments appears to me rude. What do you guys think? If you guys think it is not rude,please explain me why and explain the line which differentiate rudeness and acceptable criticism?

A:

That comment was mine. First, let me apologise for any offence you may have felt. It was not intended as a direct criticism, merely a comment; it was not intended to be rude. If you feel a comment is unwarranted, then flag it. However when I last saw it it had been agreed with by another user, so its sentiment is not entirely individual. 
It was intended to indicate that the two answers are practically identical. JR took a great deal of effort to explain how to write a good question — which boiled down to "Do the research, document that research and write a question based on that research." You then asked a closely-related question and got a closely-related answer, "Do the research, document that research and write a question based on the research." 
To answer your questions,

Ask for clarification in comments. But read the answer fully first, and again, do any research necessary. There is a user who routinely causes the scope of his questions to creep and that's not good. If you have a wholly different question, then ask that separately. In this particular case, I didn't find the questions very different, because they were both essentially "How do I ask a question?" and the answer is the same: Help the community to help you; show them your research so they don't repeat it; be very clear about what it is you want to know.
Because some full answers like JR's take effort to digest, you may need to take time to do that. Do take that time. If you have someone available with experience in English, ask them to explain it too. If you need to ask for clarification, use a judiciously-worded comment which highlights the issue with their answer. The author can update the answer if that's what is necessary. That is, don't simply expand your original question with the comment; it will be something like "Could you edit your answer to make gobbledygook clearer, please? I tried looking it up but all I found was stuff about turkeys bolting food." Make the supplementary question specific.
You may realise that an answer doesn't provide what you really need, and that you do actually need to add details to your question. Do that instead; but it's good practice to add a comment to an answer to let the answerer (and other readers) know that the question has changed and they may need to revisit their answer. 
Obviously it would not be good to do either of these things too often, which is why it's necessary to be careful in how you compose your question in the first place. Writing a good question takes time, and often the time you take in composing the question will be reflected in the time taken by those who answer. Do the research, describe what you did, say why it doesn't help, and then ask about what you need to know. JR has provided really good worked examples.
It's also good practice to use prior answers when you have a question (so searching the site is necessary). In this case, you got a very full answer about how to ask about synonyms, and then you asked "How do I ask about etymology?" to which the answer is almost identical. It is possible to apply all the techniques in the earlier answer when asking any question; in this regard it's rather like a university seminar or tutorial — you're given techniques to use. If you were actually asking "What resources can I use to research etymology," then that's a different question (even though JR has answered that as well) so you need to be very clear about what it is you actually want to know. If necessary, take the time to be sure of that yourself and to make it apparent in the question you write. It may only become apparent when you have actually tried to find an answer for yourself: at least then you know what you were looking for.
If you haven't already done so, do commit to the English Language Learners site. There are two reasons: as a non-native speaker with a good level of competence, you may be able to answer questions from those who are less skilled in the language; and if you have questions then they may fit better into that site than this one. [That's not dismissive; some questions will fit better in ELU.SE, but the dividing line will only become apparent once that site is up and running.] However even that site will expect a certain level of research and self-help.
I may not be the best person to comment on that. However, one example of "rude" would be a direct ad hominem attack, which this wasn't and wasn't intended to be.

