教学内容分析
This teaching period mainly deals with the grammar：the －ing form.In the English language，the －ing form of a verb may be a present participle or a gerund.The form is identical and the difference is in the function，or the job it does in the sentence.The present participle is most commonly used：
(1)After verbs of movement/position in the pattern.
(2)After verbs of perception in the pattern.The gerund always has the same function as a noun(although it looks like a verb)．
In this period we will focus on only part of the usages of the present participle，that is，the present participle used as the adverbial.
