I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar I thoroughly understood the entire grammar system in one article, and finally understood English grammar