英文文法又有問題...唔該各位幫幫小弟

即是第三身單數

例如:
John takes mini bus to school everyday. (每天都做的事便用現在式)
The dog eats canned food once a week.

而你的例句中為何動詞不用加s在尾, 因為這是將來式 future tense, 第三身單數之動詞要加s的是現在式present tense才會需要.

2007-04-16 20:46:03 補充：
第三身單數 - 即是 he, she, it

三身單數即是he,she,it +s
Example:
He goes to school every day.
She becomes popular after dying her hair.
It kills the competitor.

The water will become vapour and form clouds again.
Because of the *will*, behind *will* we don't need add anything. Because they are bare infinitive.
Example: After the *should, can, shall* don't need add anything.

Hope I can help you!