"We are a licensed Real Estate Agency and one of the fastest growing housing agency in Singapore."

上面這句房地產廣告中的話，望文生義，清楚易解，只可惜犯了語法上的一個大忌，就是把復數名詞變成單數：agencies→agency.

單數也可以，只是后半部的句子要作調整：“……and the fastest growing housing agency in Singapore.”

調整后的句子避免了語法錯誤，但是句子的意思有些改變，就是從“其中一個代理商”變成“唯一的代理商。”最好還是從根本的語法錯誤著手，就是把“one of……”后頭的 agency 改為 agencies.這種錯誤改正，在學生英文作文里，是司空見慣的事，不足為奇的。例如：

① South Korea is one of the Asian country that used to have student mobs.(應改為countries)

② One of the most obvious disadvantage is that the relationship between the parents and the children is not intimate.(應改為disadvantages)

從這樣的改正中可以看到在“one of……”這樣的句式中，跟著出現的名詞必須是可數復數名詞(plural countable nouns)如： countries, friends, shops, goats 等，而不是可數單數名詞如： country, friend, shop, goat 或不可數名詞(uncountable nouns ), 如：love, oil, knowledge, information 等。因此，除了上面 ①和②句子是錯的之外，③和④也不對：

③ One of the equipments was damaged.

④ I have special liking for one of the new furnitures.

③和④的錯誤來自不可數名詞 equipments 和 furnitures，因為這類名詞是不可有復數的。

其次，必須注意的是“one of……”這樣的句式當主語時，后面的動詞如果是簡單現在時態(simple present tense)的話，一定要跟 one 搭配;one 既然是單數，動詞當然也是單數，如：

⑤ One of the fastest growing housing agencies in Singapore is none other than New Century Real Estate Agency.

⑥ One of the effective ways of enriching English vocabulary is to use the vocabulary learnt.

⑦ One of the reasons for bad reading and writing seems to be that people today pay more attention to listening and seeing than reading and writing.

這樣的一致性也適用于接系動詞(linking verb)的簡單過去時態(simple past tense) “was”，如：

⑧ One of the proposals at the meeting yesterday was rejected.

⑨ One of the questions Tom raised at the news conference was irrelevant to the matters under discussion.