relative clause 的簡化

1. The popular singer is my sister.

2. Being alone, the elderly asked me for help yesterday.

“Being” is used in non-finite clauses where you are giving the reason for something.

你的兩個 relative clauses 都是屬于這類形
who + linking verb (is) + predicative adjective (popular, alone)

通常刪除 who 和 linking verb,將 predicative adjective 放置在 subject 前面, 這 adjective 都是形容同一個 subject, 唯一不同名稱, 變了做 attributive adjective,
第一句子便是這樣轉了

第二句子, 不可以這樣轉, 因為 alone 只是 predicative-only adjective (e.g.. afraid, aware), 不能作 attributive adjective, 不能放置在 subject 前面, . “alone elderly” 是錯
改了使用 present participle phrase, “Being alone”, 作句子的開頭, 有 comma 在 alone 後面. Being 在這裡有特別用法

劍橋字典有一例句
“Being afraid of the dark, she always slept with the light on.”

轉回用 relative clause
She who was afraid of the dark always slept with the light on

“The elderly alone asked me for help yesterday. “

這句中的 alone 解 ”只有自己一個人”,
“you alone know/have/can do sth -used to say that you are the only person who knows or can do something

不是解 “單獨的”~ without any other people, 孤單的﹐寂寞的 ~ feeling lonely”

“The singer being popular is my sister.”
有簡單句子”The popular singer is my sister” 不用
The longer sentence sounds unnatural
Does it sound classy?
It also invites all kinds of trouble.

Bing Translate:~
“The singer being popular is my sister. = 受歡迎的歌手是我妹妹
The popular singer is my sister.= 這位流行歌手是我妹妹”

“being popular “放置在 subject 後面, "being" 中文可解 ”正在”.”being “ 是 “be” 的 present participle, ”.”being “ 在 subject 後面多少有點動作感, in active form

還有 popular 不是 postpositive adjective, (少數形容詞)
例如 all the people present, accounts payable, God almighty,
即是一個 adjective 直接在 subject 後面來形容 subject,

如果不是 postpositive adjective, 需要 adjective phrase
Julie has given a good example.
“The singer popular with young people is my sister.”
Meaning 上少少變, popular with young people


2015-05-21 20:19:50 補充：
postpositive adj. 不是 predicative-only adj.

用 predicative-only adj. 要 linking verb 來 link subject 與 adj.
subject + link. verb + predicative adj.
The boy is afraid.
afraid 不能做 attributive adj. 所以稱 predicative-only adj.

2015-05-21 20:26:54 補充：
postpositive adjective is placed right after the noun.
noun 與 adj. 之間無任何 verb

The chemicals obviously kill any bacteria present. ( present 是 postpositive adj.)
The boy is present. (present 是 predicative adj.)
The present owner is a Jew. (present 是 attr. adj.)

Sorry, I have to go now. 有時間再談!

2015-05-22 01:43:39 補充：
The elderly alone asked me for help yesterday.
小心, alone 可以做 adj. 或 adverb, 在這句是 adverb
~ to emphasize that there is only one person who asked me for help

"The elderly who is alone asked me for help yesterday." ~ 不同 meaning
alone 做 predicative adj. 解 "單獨, 無伴" alone 前面是 linking verb

2015-05-22 02:47:29 補充：
“Being afraid of the dark, she always slept with the light on.
Being younger than the others, I always had to wear their old clothes.
Being young, he did not worry" ~.字典

"Also, being alone with my daughter, I could see how mature and successful she is." ~ "Time"

2015-05-22 20:19:57 補充：
"Being younger than the others, I always had to wear their old clothes." ~ from Macmillan 字典

其他有聲譽字典的例句, 可信性極高, 劍橋字典已出 4th edition
我信牛橋, 朗文 grsmmar 書籍多過網上的 blog
"Being ......" 這 participial phrase 是句子開頭
similar to "Turning the corner, we saw the hospital in front of us."

2015-05-22 20:34:05 補充：
Typo error: grammar, 不是 "grsmmar"

小心, participial phrase 的 subject 是 main clause 的 subject
除了一些 common phrases, e.g. "Frankly speaking, ...."

Turning the corner, the hospital was iin front of us. ~ 錯

2015-05-23 20:17:40 補充：
另外一說法, 用 adjective phrase 作 appositive, 有兩個 commas, non-defining 性質
意思變了些少, 通常 appositive 多數是 noun phrase

The elderly, alone without any close friends, asked me for help yesterday.

"being+adjective" 放在 subject 後是否正確?
我先聽其他網友意見, 純知識交流

2015-05-24 07:59:46 補充：
你給 thread, The weather being hot， we had to stay at home.
being hot 不是形容 subject, "we"
是形容 weather, The weather being hot 不是 adj. phrase, 是作状语 adverbial

"being+adject. "放在 subject 後是否正確?
只有 Jenkin 說正確

你選擇那個?
1 My young son had a cold yesterday.
2 My son being young had a cold yesterday.

2015-05-25 07:59:06 補充：
Summary:
relative clause 的簡化

In defining clauses we can leave out the relative pronoun and part of the verb phrase to leave a past participle or a present participle acting as an adjective to define the noun.

2015-05-25 08:14:30 補充：
In non-defining clauses reduced clauses often occur in descriptive writing.

You can't reduce a relative clause with "be" followed by a single adjective in this way.

Being alone, the elderly asked me for help yesterday.
Even 這句, "Being alone" gives the reason for the action.

2015-05-25 08:22:28 補充：
結論:

句子 (1), (2), (4) 錯
(3) 是 grammar 對, 但 meaning 不同

2015-05-25 08:34:31 補充：
The singer being popular is my sister. ~ 錯
The popular singer is my sister. ~ 對

Writing plain English isn't easy:
You have to think hard about what you are going to say, why you are saying it, and who'll be reading it.

Thanks, Julia.

2015-05-25 10:29:01 補充：
Sorry, 可能我講得詞不達意

In defining clauses:
This is the only painting (which was) not sold during exhibition.
Most of the people (who were) waiting for tickets went away dissappointed.

In non-defining clause:
The policeman, (who was) covered in blood, went back to the car.

2015-05-25 11:06:30 補充：
The singer (who is) popular is my sister. ~ 單 delete "who is" 錯
The popular singer is my sister. ~ delete "who is" , popular 移去 singer 前
不同前三句, 不是每個 adj. 可以

Being alone, the elderly asked me for help yesterday. ~ grammar 對, meaning 不同
Being alone 是原因 , 必定放置句子前, 有 comma

2015-05-25 11:32:07 補充：
其實 The lone elderly asked me for help yesterday. 更貼切, lone 是另外一個 adj.

o reduce a relarive clause "who + be + adj." 是無 rule 可跟, may follow a guideline

The house (which is) on sale includes a garage.
on sale ~ preposition phrase

英語除了 grammar, 要考慮 usage, 適當的 word 很重要

2015-05-25 19:18:42 補充：
This is the only painting not sold during exhibition. ~ 無問題

"who had not seen her for fifteen years or so" 是 non-defining, past perfect tense
having not seen 雖然有 perfect aspect, 是 non-finite verb in a participal phrase
having not seen her for 15 years ,, 是 reason, 可放置前或後

2015-05-25 19:24:47 補充：
Having not seen her for 15 years or so, he failed to recognize her at first ~ also OK
"Having not seen her for 15 years or so" gives a reason for failing to recognize her.
一定有 comma

It is 7.25 am. I have to go now.

The popular singer is my sister. (adjective - single word)
The singer popular with young people is my sister. (adjective phrase)
"popular with ..." 深受年輕人的喜愛

就你提出的選擇來講：

The singer who is popular is my sister. ->
(2) The singer being popular is my sister.

The elderly who is alone asked me for help yesterday. ->
(4) The elderly being alone asked me for help yesterday.

其實你自己的原則已經解釋了，因為兩個/句都是SUBJECT，動詞還是形容詞等關於這SUBJECT的情況只是句子表達的內容，跟以WHO來附加/連接或改寫沒有文法上的分別。