1.分词就是具有动词及形容词二者特征的词，尤指以-ing或-ed,-d,-t,-en或-n结尾的英语动词性形容词，具有形容词功能，同时又表现各种动词性特点，如时态、语态或带状语性修饰语的性能及带宾词的性能。
1)有一定的逻辑性。
E.g. Having finished her homework, the girl went happily to the movie.
2)可起到使句子简洁明确的作用
比较:
2. lie; lay 傻傻分不清?往下看!原型 lie lie lay
过去式 lied lay lain
过去分词 lied lain lain
说谎 躺 下蛋
顺口溜巧记:千篇一律的撒谎
不规则的躺
规则的原型lay下蛋
3. 如果句中的主句或从句有假设的意思，那么就要用主将从现。
E.g. I will visit you whenever I get a chance.
4.限制性定语从句: 先行词不可缺少，去掉先行词主句意思往往不明确；
非限制性定语: 从句是先行词的附加说明，去掉了也不会影响主句的意思。
E.g. Mr.Yang whom I hate asks us to write an article every week.(错)
Mr.Yang, whom I hate asks us to write an article every week.(√)
5.指示代词语气很强烈，一定放在开头。E.g. Here comes a bus.
6. 区分: therefore与so
however与but
so和but是连词，可以连接两个简单句；但是，therefore和however是副词，不能直接用来连接两个简单句，想要正确使用，就要注意标点符号的合理辅助以及句子的结构安排。
E.g. I studied very hard, so I got a good grade.
I studied very hard; therefore, I got a good grade.
I studied very hard. Therefore, I got a good grade.
I studied very hard; however, I didn't get a good grade.
I studied very hard. However. I didn't get a good grade.
由此可见，只需要在therefore和however的前面用句号或分号隔开，后面用逗号隔开即可。
你学会了吗
