Subject + predicate as topic and prepositional phrases

Question

I found this sentence while doing some listening practice:
长时间看电脑，对眼睛不好。
At first, I didn't understand why 长时间, expressing duration, is at the beginning of the sentence acting as topic 长时间看电脑, since I learned that these are usually placed at the end of the sentence or between the verb and the object (depending on whether the verb is transitive or not). I tried asking online and it turns out that when a sentence acts as a topic of a sentence, the word order can be quite different. I got other example sentences:
在罗马待的一个星期给我留下了很深的印象。
三年的汉语学习使我能和中国人流利地交流。
Is this a matter of pure habit or are there some strict rules governing word order in sentences that act as a topic?

Answer 1

It differs on how you want your message to be received:

长时间看电脑，对眼睛不好。- Staring on the computer for a long period of time is bad for your eyes. (An act + predicted result for the act)

那对眼睛不好, 如果长时间看电脑(的話). - That is not good for your eyes if staring at the computer for a long period of time. (Result + act that leads to the result)

If you want to be brief and authoritative, the former is preferred, otherwise, say the latter, which is more a bit of advice for the other's well-being.

Similarily,

在罗马待的一个星期给我留下了很深的印象。(A brief statement) You can say,

那给我留下了很深的印象在罗马停留的一个星期中. (A more descriptive sentence) And,

三年的汉语学习使我能和中国人流利地交流。(A brief statement) You can say,

那使我能和中国人流利地交流經過了三年的汉语学习後。(A more descriptive sentence)

Note that the more descriptive sentence of both these cases, while acceptable, is not a very good sentence.

Answer 2

Your subject of the sentence could be anything, as long as you make it clear to the listeners what it is.

After breaking down these sentences, you could see that Mandarin and English just have the order of their SUBJECT and subject description reversed.

Mandarin Structure
(Short description to describe the subject/event) + (SUBJECT/EVENT) + (Outcome of the event)

English Structure
(SUBJECT/EVENT) + (Short description to describe the subject/event) + (Outcome of the event)

长时间 + 看电脑 + 对眼睛不好。
Looking at a computer + for a long time + is bad for the eyes.

在罗马待的 + 一个星期 + 给我留下了很深的印象。
The week + stayed in Rome + gave me deep impression.

三年的 + 汉语学习 + 使我能和中国人流利地交流。
Learning Mandarin + for three years + made me able to communicate with Chinese fluently.

In general, as long as you don't make the first part too long -> (Short description to describe the subject/event), then people will be able to understand the (SUBJECT/EVENT) you're trying to tell..but even the example below would work:

三年內每天一百下伏地挺身,一百下仰臥起坐,一百下深蹲,十公里跑步的 + 這種健身方式 + 讓他最後變成了禿頭。
The workout routine of 100 push-ups, 100 sit-ups, 100 squats, and 10km running for three years eventually made him bald.

Just create more sentences of your own to practice, then you'll get the idea.

Answer 3

Placement of adjectives and adverbs in Chinese

0. A phrase is grammatically incomplete but can be semantically complete. A sentence is complete both grammatically and semantically. Compare Examples 3a. and 6a. below. Ungrammatical examples are labelled with an asterisk.

1. When 的 is used to attribute a quality to a noun, or indicate possession, the adjective always precedes the noun. The resulting phrase is nominal.

1a. 高興的人們 merry men [attributive]

1b. 我的貓 my cat [possessive]

2. When 地 is used, the adverb always precedes the verb. The resulting phrase is verbal.

2. 高興地跳舞 to dance merrily

3. The attributive 的 or 地 can be omitted out of formality, concision, or when there is no ambiguity.

3a. 無私的行為 > 無私行為 a selfless act [formality]

3b. 長時間地勞動 > 長時間勞動 to labour for a long period of time [concision]

3c. 學了英語三年的他 > *學了英語三年他 he who learned English for three years [ambiguity]

4. The possessive 的 cannot be omitted.

4. 我的貓 > *我貓 my cat

5. The attributive 的 and 地 are omitted in compound words or set phrases.

5a. *熱的情 > 熱情 passion (lit. hot emotion)

5b. *熱地愛 > 熱愛 to be fond of (lit. hotly love)

6. When a sentence states the quality of a noun, the adjective follows it.

6a. 行為無私。 The act is selfless.

6b. 他很高。He is very tall.

7. When 得 is used, the adverb of extent follows the verb within the phrase. The resulting phrase is either adjectival or adverbial.

7a. 學得慢 learning slowly

7b. *學得慢。[not a sentence]

7c. 他學得慢。He learns slowly. [adjectival on 他] [by Rule 6.]

7d. 他學英語學得慢。He learns English slowly. [adverbial on the first 學]

8. 了 replaces 得 when the adverb of extent within the phrase is temporal. Likewise, the adverb of extent follows the verb. The resulting phrase is either adjectival or adverbial.

8a. 寫了三天 wrote for three days

8b. *寫了三天。[not a sentence]

8c. 我寫了三天。I wrote for three days. [adjectival on 我]

8d. 我寫論文寫了三天。I wrote a thesis for three days. [adverbial on the first 寫]

Please see if the lengthy examples you provided follow the above rules.