《由標點符號引起的錯句》里談到不完整和無休止的句子(run-on sentences)時，我曾指出句子不可以一個接一個，只有逗號，沒有句點。

和不完整的句子有些相似的是不完整的結構(incomplete constructions)。這種結構屬高層次情況，偶爾出現，也不奇怪，但是若能避免，那就更好了。

什么結構是不完整的呢?原因何在?

顧名思義，不完整結構就是一個結構中欠缺了某個語言成分，以致不合規格，導致句法上的困惑。例如下列這個句子便出現結構不完整的瑕疵：

“Thank you for your continuous interest and support for our magazines.”

這里要感謝的事有二：對雜志的興趣與支持。

英譯中不成問題，但“interest”后面要加“in”才可以和“support for”對稱。缺少了“in”，這結構便不完整了。像這種情形，最好將兩件事分開，因此，上面那句話可以改寫如下：

“Thank you for your continuous interest in our magazines and your strong support for them.”

同樣的，下面三個結構不完整的句子，也要作適當的調整，使句子的意思清楚易解：

① Sam is good and successful in painting.

② The Chairman’s argument was sound and adopted without any discussion.

③ Professor Chen has taught in many universities, London University and Harvard University.

在①句里，必須在“good”后面補上漏掉的介詞“at”。在②里的第二個并列句的“……adopted……”是個被動式，前面的助動詞“was”不可省。③里的“many universities”包括了所提的兩所，所以要在它們前面加“including”或“such as”，才合邏輯。不然全句要改寫如下：

“Professor Chen has taught in London University, Harvard University and many other universities.”

上面句子不是忽略了介詞，便是少去了助動詞等。還有些不完整的結構是發生在比較句中。例如：

④ Many buildings in Singapore are as modern as any other city.

這里把“buildings in Singapore”和“any other city”相比，邏輯何在?應該調整為建筑物間的比較才對：

“Many buildings in Singapore are as modern as those of any other city.”

⑤ The athlete is as strong, if not stronger than, the wrestler.

英語里的“as……as……”是連用的，因此這句要改為“The athlete is as strong as, if not stronger than, the wrestler.”但是為了緊湊起見，全句可改寫如下：

“The athlete is as strong as the wrestler, if not stronger.”

⑥ Japanese cars use less petroleum.

這句話的小毛病是，另外一樣被比較的東西不詳，要補上使結構完整。

“Japanese cars use less petroleum than European cars.”