You are studying in a field that is referred to as binary (true or false). Language has nuances, subtleties, slang, etc; however, those that master their native tongue as well as another know that little details mean a lot. Bravo to you! "How long has he played soccer?" You may expect that the answer would be, "He has played soccer for 10 years", however, the reply could be "He has played since he was age 5". You may use either tense, as you've described but imagine that you are creating a survey and what you really wish to know if the number of years that they have been playing soccer. In that case I would advise you to be more specific in how you craft your question. For example, "How many years have you been playing soccer?" "How many years did you play soccer?"(the latter denotes they no longer play). In verbal dialog exchange, we compensate for the fluid lack of precision in our exchange. When the communication is no longer interactive, it requires more careful crafting. Hope this helps!

You have defined the difference well and your examples are good.