Are there any issues with submitting conference papers in one language and publishing them in a journal in a different language? I have some research I want to present at a conference in my native language but I would rather submit for publication in English after finalizing it. Are there any ethical issues with this I am missing?
As stated in the comments. It is totally irrelevant if they are in two languages. If it would be ethical to do this one language then it will be ethical in two. If it is unethical in one language then it will be unethical in two. In my field presenting at a conference and then submitting a paper to a journal is just fine, as long as the conference does not publish a proceedings or similar. In other fields, it is not acceptable. Again, the language matters not.