Preposition後的動詞要加ing

Participle phrase (especially long) written in a natural way:

Thinking (that) the journey would take two days, the boy said (to his mom that) he would probably not be back until a week after.

2015-05-23 07:20:19 補充：
1. preposition + gerund / gerund phrase

若動名詞後面仍有動詞, it has to be non-finite, including, participle, gerund and infinitive.

例: We are capable of compelling the package contrator finish their work as soon as possible.

format: compel somebody to do something
The verb after "compel" has to be a non-finitite verb of to-infinitive.

~ We are capable of compelling the packing contrator "to finish" their work as soon as possible.

"to finish their work ...." is an infinitive phrase acting as a complement to the object "the packing contrator".


2. Participle phrase

Participle phrase can be a reduction of defining relative clause by changing the main verb into participle, a type of non-finite verb.

The boy who broke the glasses (眼鏡) is my brother. (defining relative clause)
The boy breaking the glasses is my brother. (reduced participle phrase)

As you can see, the participle doesn't carry the information of tense from the relative clause.

Participle phrase (especially long and as a reduction of non-defining relative clause) can be written in a natural way:

Thinking (that) the journey would take two days, the boy said (to his mom that) he would probably not be back until a week after.

句子除了文法格式外還要考慮(或者應該說是詞組的合理/邏輯表達)才能成立的，不是單單把一些詞轉換便一樣的。以上嘗試解釋。


He is good at playing football.
的playing動名詞可以這樣放是因為前面GOOD AT意義上連接是要形容一個NOUN而不是動作或形容詞。

你問
We are capable of compelling ...名詞後仍有動作(動詞)要講時，那便要寫成"to infinitive"，即是
... the package contractor TO finish their work as soon as possible.


問題二
The boy breaking the glasses is my brother.
(breaking the glasses 用以修飾的是顯示誰是這個男孩是"我兄弟")

類同

The boy thinking the journey would take two day said....
(thinking the journey would take two day用以修飾的是顯示是誰(那一個男孩認為行程需要兩天)在SAID講...後面你冇寫出的內容)

不過坦白講這兩句用這種particple clause並不太好，雖然不可算錯，但是因為修飾的內容"breaking/thinking"並不是這男孩的特質而是一個場景/事件，可能嚴格的文法可能要求是

The boy who broke the glasses, is my brother.
The boy who thinks the journey would take two day said...

你都識講是PARTICPLE CLAUSE即是CALUSE裏是獨立片語或表達定義性質的內容。因此不是一切變為present participle便是合適的。