Museum of Knowledge is often asked, is it possible to write well in two languages? Learning two languages at the same time requires high skills and competence and some language learners can be confused and accidently confuse words and tenses in the two languages that they are learning. For those who have reached a high level of competency perhaps at advanced level, it may at this stage become more and more feasible to write well in two languages.
One of the key things to bear in mind is that the two languages spoken should at least be at the same level, which will make it far easier to write well to a high standard in two languages simultaneously.