In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Q: What is the second to last variance listed in the text, Context: Catalan is split in two major dialectal blocks: Eastern Catalan, and Western Catalan. The main difference lies in the treatment of unstressed a and e; which have merged to /ə/ in Eastern dialects, but which remain distinct as /a/ and /e/ in Western dialects. There are a few other differences in pronunciation, verbal morphology, and vocabulary.
A:
morphology