由 for 构成的介词短语在句中可用作以下成分：

1. 表语

That’s for you. 这是给你的。

The house is for rent. 此房屋出租。

This is for your reference. 这仅供你们参考。

The appointment is for 12 May. 约会定在5月12日。

This medicine is for external use only. 这种药仅限于外用。

His fundamental concern was for her welfare. 他最关心的是她的幸福。

The gifts were intended for you, but Mary thought they were for her. 这些礼物原来是要给你的，但玛丽以为是给她的。

2. 状语

Eggs are good for you. 鸡蛋对你有好处。

Let me do it for you. 让我替你做吧。

I am sorry for her. 我为她难过。

He is learning French for fun. 他学法语是为着好玩。

Let’s sit down here for a while. 我们在这里坐一会吧。

I made this cake especially for you. 这蛋糕是我专门为你做的。

I have been here for the last two weeks. 最近两周我一直在这里。

He stayed there for a week during the summer. 夏天他在那儿呆过一周。

3. 定语

Here is a letter for him. 这里有封信给他。

Here is something for you. 这一点点东西是送给你的。

I’ve booked a table for two. 我预订了一张两个座位的餐桌。

There were an astonishing number of applicants for the job. 申请这份工作的人数多得惊人。

We appreciate your efforts for the development of the company. 我们感激你对公司发展所作的努力。