“They are wasting resources, for example, time, energy and money.”

上面這句話不錯，只是轉折詞“for example”不妥當;應該這樣：

“They are wasting resources. For example, they use too much time, energy and money.”

不然就要換一換轉折詞，改用“such as”或“like”：

“They are wasting resources, such as (or like) time, energy and money.”

不管任何語言，轉折詞(transitional words)都扮演著一個重要角色，就是：承先啟后，使句子緊湊，段落相吸，對文章結構，有良性作用。但是有些人幾乎沒有采用轉折詞的習慣，結果文句松散，上下文七零八亂，應該避免。

現在把主要轉折詞，分類列下，供大家參考。

Ⅰ表示“尤有進者”的意思：

Again, also, then, besides, further, furthermore, moreover, next, in addition等，如：

① Jason teaches diligently. Besides, he writes a lot.

② English is a useful language. For one thing, it is an official language in the UN. Then, it is widely used in business, science and technology.

Ⅱ表示“反意見”：

But, however, still, yet, after all, for all that, in spite of, on the contrary, on the other hand等，如：

③ Jim is intelligent but lazy.

④ Singapore is not a big country.On the contrary, it is very small.

Ⅲ表示“困果關系”：

Therefore, so, hence, thus, accordingly, consequently, as a result 等，如：

⑤ Some people are over-ambitious. As a result, they are usually unhappy.

⑥ Tom did not work hard; hence, he failed.

Ⅳ表示“比較關系”：

Likewise, similarly, in a like manner 等，如：

⑦ You cannot writes without a pen. Likewise, you cannot cook without rice.

⑧ No one is allowed to speak Mandarin in an English class. Similarly, no one is allowed to speak English in a Mandarin class.

Ⅴ表示“舉例示范”：

For example, in other words, for instance, that is 等，如：

⑨ There are some common errors in his composition. For instance, it is wrong to use "he" to replace "the queen".

Ⅵ表示“結束”：

To sum up, in brief, in short, on the whole, to conclude 等，如：

⑩ Some say Singapore is a nice place to live in. Others say it is not so nice. It is too competitive. In short, some like Singapore; some do not.