英语句法学习的核心内容：五种基本句型、存在句（重中之重）；简单并列和复合（能判断）；定从名从和状从（识别从句、判定引导词）；谓语动词时体态（一般现在、一般过去、现在完成）；非谓语动词主被动。这是句法分析和句子构建的核心理论，是英语句子的底层逻辑。句子构建的基本模型为：主干+修饰。再具体一点，即：介短【非谓、从句（状）】+核心句+非谓【介短、从句（定、状）】。我们还可在此模型基础上，运用并列和复合的手段，构建更为复杂的句子。我们如果留心观察，会发现在日常阅读中，这样的结构随处可见。
1. In the most southwestern part of China, the mountainous Yunnan province, you can see wild tea trees that have stood there for thousands of years.
2. Since the Han dynasty, these trees, or more specifically their leaves, have been used to make special varieties of black tea and to this day Yunnan remains one of the most important tea-producing regions.
3. While the climate is generally mild and humid, and rain falls regularly, the landscape ranges from snow-capped mountains in the north to subtropical low-altitudes in the southeast.
4. Having lived for hundreds, if not thousands of years, these ancient trees have taken in many minerals and nutrients from rich soil, adding the complexity and uniqueness of the flavor of the tea.