Hi Beth, 我发现你所有问的问题都好难哦，即时是母语的人，也很难描述一个“规则”出来。 呵呵。 new computer games for his ps2 为他的PS2准备的新电脑游戏 能用于他的PS2的新电脑游戏 针对他的PS2用的新电脑游戏 这些说法应该都能表达出你的意思。

Hi, Beth. In fact, it concerns a big difference between English and Chinese. Unlike English, there can be several verbs in only one Chinese sentence. Sometimes, or I may say most of the times, English conj like 'for' 'to' etc become verbs when they are translated to Chinese. Under such circumstance, it is not the problem of Chinese conj any more. 'For' in 'new computer games for his ps2' you can say:适用于ps2的电脑游戏 e.g. This programme is for PC, not for Macintosh. In Chinese would be:该程序适用于PC机，不适用于苹果机。 'for' in Chinese mean more than just a conj, it can be a conj, or a verb, depending on the whole sentence it is used in. It looks simple as a three letter word, but it is a very big issue to talk about. Here, I only give you the translation of 'for' as in the sentence you mentioned. I hope you remember, 'for' is far more than that. If I look up for it in the dictionary and list the usages here, they would only confuse you.

1 used to show who is intended to have or use sth or where sth is intended to be put (给，对，供）example:1）There is a letter for you. 有你一封信 2 ）its a book for children这是本儿童读物 3 ）We got a new table for the dining room 我们给饭厅添了一张新桌子。 2 in order to help sb/sth 以帮助，为了 example;1)what can I do for you？有什么事我可以为你效劳么？ 2）can you translalte this letter for me ?你能为我翻译这封信么？ 3 concerning sb/sth 关于 example：1）they are anxious for safety 他们为她的安全担心 4 as a representative of 代表 ex：I am speaking for everyone in this department 我代表这个部门的全体员工发言 5 employed by 受雇于 she is working for IBM 她在IBM公司工作 6meaning 意思 shaking your head for "no" 摇头是不得意思 7in support of 支持；拥护 Are you for or aganist the proposal 8 used to show purpose or function 表示目的或功能 ex： lets go for a walk 咱们去散散步 9used to show a reason or cause 因为 由于 ex ：the town is famous for its cathsdral 这个城镇以大教堂著名 10 used to show where is goning 往 向 ex ：is this bus for Chicago？这辆车是去芝加哥的么？ 11 used to show a length of time 表示一段时间 ，距离ex ：i am goning for some time 我要离开一段时间 the road went on for miles and miles 这条路绵延数英里 Hi , you can let your friend who is in china buy a << ADVANCED LEARNER`S English-Chinese Dictingnaty>> for you I used it to improve my English . but it can also help you learn Chinese better! (*^__^*) 嘻嘻…… Can you add my MSN？it is zaiyang009live.cn 。I want to be your friend

I think you can try this.For example: "A" for "B". you need to know "A"grammar and "B" grammar.if "A"is noun ,and "B"is noun.then......"for" ,you can translate it<代 dai 替 ti;代 dai 表biao > like this sentence:"We used boxes for chairs." If "A"is verb and "B" is noun,then....you can translate it <朝...方向去;往,向> like this :"He left for Beijing" if you learn more chinese vocabs you won`t vexation for that! my english is so bad ,i hope you can read it .

If you need ,I am willing to help you.