从这个问题以及前面提出的类似问题，可以看出，网友对动名词作表语（尤其动名词是being 时），存在很大误区。

这是受了错误术语“现在分词作表语”的严重影响和误导！把现在分词和动名词、把动名词作表语和进行时态，混为一谈。

譬如网友曾经问过，下句being 为什么不能省略？

The only thing to worry about is being afraid of them.

本句的being 决不可省略。省略后貌似正确，其实是大错特错！原因是：is afraid of them 的主语只能是“人”，不能是the thing。

being afraid of them 是动名词短语，作 is 的表语。它跟the thing 是对等关系，可以倒过来说：

A 是 B;  B 是 A

The only thing to worry about is being afraid of them.

【翻译】唯一需要担心的就是害怕他们。

Being afraid of them is the only thing to worry about.

【翻译】害怕他们是唯一需要担心的事情。

网友还问：being 为何一般不省略。—— 我认为，不是一般不省略，而是坚决不能省略！因为省略后，意思、逻辑根本不通！

being 也是动名词，动名词短语作表语时，动名词决不可省略。例如：

His job is driving a car. 他的工作是开车。

driving 能省略吗？

His job is a car. ——？？？？

下面，请网友认真阅读我的详细解答，试图彻底解决你的问题。

（一）动名词作表语和现在分词作表语

【注】“现在分词作表语”，这是一个伪命题。详情参见我的拙作：

《“现在分词、过去分词作表语”这个语法术语应废止》

http://www.yygrammar.com/Article/201305/3211.html

1. Her job is looking after children.

2. Her job is boring.

句1的意思是：“她的工作是照料孩子。”这是动名词短语looking after children作表语。因为is是系动词，主语和表语是平等的并列关系，所以可以互换而意思保持不变：Looking after children is her job.

句2的意思是：“她的工作很无聊。” 这就是所谓的现在分词boring 作表语，其实是形容词boring 作表语。由于它是由使令性动词bore 变化而来，具有很强的主动使令意味。所以，可以转换为一个主谓宾的句子：Her job bores her. “她的工作令她厌倦。”

因为动名词具备了名词的语法特征，所以，既然名词能作表语，那么动名词完全可以作表语。例如：

His hobby is collecting stamps. 他的业余爱好是集邮。

His ambition is working as a lawyer. 他的抱负是当律师。

The only way to cure your disease is going to bed. 治疗你的病的唯一办法是上床睡觉。

Her job is keeping the offices clean. 她的工作是给办公室保洁。

Her work is teaching children music. 她的工作是教孩子音乐。

His only wish is finding a job in an office. 他唯一的愿望就是找一份办公室的工作。

The ant queen’s full-time job is laying eggs. 蚁后的专职工作是产卵。

The boy’s hobby is playing games online. 这个男孩的爱好就是玩网上游戏。

My favourite sport is playing tennis.我最喜欢的运动是打网球。

Her first delight was going to the Tower. 她第一个想做的事情是参观伦敦塔。

以上例句中，主语和表语是平等的并列关系，所以可以互换位置而意思保持不变。例如：

His hobby is collecting stamps. 他的业余爱好是集邮。

→Collecting stamps is his hobby. 集邮是他的业余爱好。

His ambition is working as a lawyer. 他的抱负是当律师。

→Working as a lawyer is his ambition. 当律师是他的抱负。

The only way to cure your disease is going to bed. 治疗你的病的唯一办法是上床睡觉。

→Going to bed is the only way to cure your disease. 上床睡觉是治疗你的病的唯一办法。

现在分词作表语，说明该现在分词具备了形容词的作用。它表示句子的主语所具备的某种性质，这个性质是主动的，具备使令意味，让人发生情绪上的变化。

Tom’s progress in English is satisfying. 汤姆在英语上的进步是令人满意的。

The examination result is discouraging. 考试结果很令人沮丧。

Her facility in languages was surprising. 她在语言方面的才能令人吃惊。

The story about space travelling is interesting. 那个关于宇宙旅行的故事很有趣。

The film was boring to a degree. 这部影片非常枯燥。

The speed of the car was frightening. 这辆小汽车的速度真吓人。

The songs we heard last night were most inspiring. 昨晚我们听的歌曲很令人鼓舞。

The jokes he told us was amusing. 他给我们讲的故事很有趣。

It was amazing that he knew nothing about the event. 他对这个事件毫不知情，真让人感到诧异。

The service here is disappointing. 这儿的服务令人失望。

It is astonishing to me that he should be absent. 他竟然缺席,使我大为惊异。

That game was not very exciting. 那场比赛并不怎么精彩刺激。

The people upstairs are very annoying. 楼上的那些人非常吵闹。

The spelling of English is often puzzling. 英语的拼写常常使人伤脑筋。

The meaning of this word is confusing. 这个词的意思很令人费解。

I don't like making speeches in public; it's so embarrassing. 我不喜欢在公开场合演说，太难为情了。

My job can be very frustrating sometimes. 我的工作有时非常令人无奈。

The soft music sounds very pleasing to the ear. 那轻柔的音乐听起来十分悦耳。

The overall picture for farming is encouraging. 农业的总体形势是令人鼓舞的。

This work is tiring; it has tired me out. 这工作很累人，可把我累坏了。

Walking in the rain is really most fascinating. 雨中漫步的确非常令人陶醉。

The news from the front is very disturbing. 来自前线的消息令人极为不安。

The crawl of a snake is terrifying.  蛇爬行起来真可怕。

以上例句中的现在分词，说明主语具备了“使令”的意味：令人感觉如何。我们可以把这个分词转换为动词作句子的谓语，后面补上所缺的宾语。例如：

The service here is disappointing. 这儿的服务令人失望。

→ The service here disappoints us. 这儿的服务令我们失望。

Her facility in languages was surprising. 她在语言方面的才能令人吃惊。

→ Her facility in languages surprised us all. 她在语言方面的才能令我们吃惊。

The speed of the car was frightening. 这辆小汽车的速度真吓人。

→ The speed of the bus frightened the passengers. 这辆汽车的速度吓坏了乘客。

（二）动名词作表语和进行时态的区别

“动名词作表语”和“进行时态”形似而神异。请看这两个句子：She is looking after the children.和Her job is looking after the children. 它们太相似了，只是主语不同，其他成分完全一样，意思却大相径庭，这是为什么？

这确实是一个很有意思的问题。Her job is looking after the children. 意为 “她的工作是照料孩子的。” 本句中，is 是系动词，looking after the children是动名词作表语。因为is是系动词，主语和表语是平等的并列关系，所以，主语和表语可以互换而意思保持不变：Looking after the children is her job. 照料孩子是她的工作。

She is looking after the children. 意为“她正在照料孩子。”本句中，is是助动词，跟动词look的现在分词构成进行时态，所以is前后两部分不能互换。不可说：*Looking after the children is she. 又如：

His hobby is collecting stamps. 他的业余爱好是集邮。

→Collecting stamps is his hobby.

He is collecting stamps. 他正在集邮。

不可说：* Collecting stamps is he.

His ambition is working as a lawyer. 他的抱负是当律师。

→Working as a lawyer is his ambition.

He is working as a lawyer. 他正在以律师的身份工作着。

不可说：*Working as a lawyer is he.

【规律】A代表“主语”，B代表“动词-ing形式”：

“主系表结构”：A is B. 可以说：B is A. （is意为“是”）

“进行时态”：A is B. 不可以说：B is A. （is doing意为“正在做”）

请区别以下例句中，哪些是动名词作表语的例句，哪些是进行时态的例句。

His hobby is collecting stamps. 他的业余爱好是集邮。

His ambition is working as a lawyer. 他的抱负是当律师。

The only way to cure your disease is going to bed. 治疗你的病的唯一办法是上床睡觉。

Her job is keeping the offices clean. 她的工作是给办公室保洁。

Her work is teaching children music. 她的工作是教孩子音乐。

His only wish is finding a job in an office. 他唯一的愿望就是找一份办公室的工作。

The ant queen’s full-time job is laying eggs. 蚁后的专职工作是产卵。

The boy’s interest is playing games online. 这个男孩的兴趣就是玩网上游戏。

My favourite sport is playing tennis. 我最喜欢的运动是打网球。

Her first delight was going to the Tower. 她第一个想做的事情是参观伦敦塔。

The scientist is doing experiments no one has so far attempted. 科学家正在作一项迄今为止没人做过的实验。

According to these figures, our company is doing well. 从这些数字来看，我们的公司经营得不错。

The teacher is reading Tom’s English paper. 老师正在审阅汤姆的英语答卷。

He always makes careful notes while he is reading. 当他阅读时，他总是仔细作笔记。

The witness was telling about the whole accident. 目击者正在讲述整个事故的过程。

He is working in his photographic studio. 他正在摄影室工作。

The sculptor is working on a sculpture of Venus.  那个雕刻家正在雕一个维纳斯雕像。