I want to know the answer to the following question:
By the thirteenth century, what had the Czech language separated from?
All the background I'm provided with is that "Its use of cases differed from the modern language; although Old Czech did not yet have a vocative case or an animacy distinction, declension for its six cases and three genders rapidly became complicated (partially to differentiate homophones) and its declension patterns resembled those of Lithuanian (its Balto-Slavic cousin).". Is that enough to answer the question?
Answer: no