英語文法 （關於 to 的問題）

How to prevent the apples become sour. 這句的文法有沒有問題呢？

You don't need the determiner "the" as you're talking about apples in general.

Second, you need a question mark at the back of a question.

Revised:

How to prevent apples become sour?

How to prevent ....... becoming......? 這句對呢？

No, it doesn't work as become means a process: from sweet to sour.

to 後面的第二個動詞是不是也要加 ing 呢？有沒有特別的情況？

It depends on what you are going to say.

Compare:
I look forward to seeing you again.
Are you trying to get shot?

2011-08-11 14:36:34 補充：
Hahatse gave a good answer and did remind me some basic problem. When we ask someone a question, we should say like this: How do you prevent apples from becoming sour? or How do we prevent apples from being sour?

Examples:
How do you do?
How does it work?

How to prevent the apples to become sour?和How to prevent the apples becoming sour?兩句都對

可參考"How to prevent spam emails to become worst?"-http://albertmikha.com/6-tips-to-prevent-spam-emails-to-become-worst/

2011-08-23 11:25:31 補充：
hahatse,
在雅虎知識網，我的意見是就問者所問的網上practical「隨便」英文而發。請勿見怪！:)

我推薦您一個非常不錯的英語學習網站，里面有很多非常不錯的學習資源：

http://www.hkenglishstudy.info

希望可以幫到你!

how to 中文為 (如何去做一D 野)
V+v-ing
eg. go hiking, watch them playing

唔好太仔細去研究一字, 因為這是蠢的做法
外國人都錯都唔關注既語言問題﹐ 為何要這樣執著！

可以去FACEBOOK 問,,好快有人答
支持下FACEBOOK 平台啦

EnglishShare
http://www.facebook.com/#!/pages/EnglishShare/116718348427333

若你留意你的問句的話，你的問句缺乏了一個主詞，所以，正確的問法是

How do you prevent the apples (from) becoming sour?
注：(from)可以省略

希望幫到你！

2011-08-11 11:36:33 補充：
若你留意句子中的from可以省略的話，你就會明白為何必定要用動名詞

2011-08-21 22:30:23 補充：
eicachan：

謝謝你引用的網站，但我卻有另外的意見

記得在廿多年前，在理工上英文課時，一位外籍老師就特特指出：

要記得說How do you ....?而不可說How to...?
當然相信他所指是：正式的英語，而不是隨便的英語

另外，英文學者michael Swan在Practical English Usage第437條，就清楚說明：

＂prevent...from...ing防止...，使...不能（不能說：to)＂

有時，網上用語，但求表達意思，會比較隨便，所以，不應效法

雖然我們的意見不同，但也欣賞你是一位用心幫助人的人