然而，當 half 前面還有 one, two … 等數詞時，則只能使用 a half，不可使用 half a/an。例如：
- Emily was talking well by the age of two and a half. (艾茉莉兩歲半的時候就很會說話)
- At least one and a half thousand people emigrate every year. (每年至少有 1500 人移居國外)
必須注意的是，one and a half (一又二分之一、一點五或一個半) 後面所接的名詞有單複數兩種寫法，所以動詞也會有單複數之分。例如：
- One and a half months have passed since we married. (我們結婚至今已過了一個半月) － 計量單位 (units of measure) 前面的數字，除非剛好是 1，否則不管大於 1 還是小於 1，單位都要用複數形式。
- A month and a half has passed since we married. (我們結婚至今已過了一個半月)
下面將各舉數例來說明 half 的名詞、形容詞和副詞用法。
Half 當名詞用：
- Our team scored two goals in the first half. (我們球隊在上半場進了兩個球)
- Prices fell by over 20% during the second half of 2000. (2000 年下半年的物價下滑逾 20%)
- The crime rate has been reduced by half. (犯罪率下降了一半)
- Johnson started school when he was five and a half. (強森五歲半時開始上學)
Half 當形容詞用：
- Jason ordered a half bottle of red wine. (傑森點了半瓶紅酒)
- We sold 500 tickets in the first half hour. (我們在前半小時賣了 500 張票)
- They’re offering the flowers for almost half price. (他們以近乎半價供應/出售花卉)
- The fearsome creature was half man and half beast. (這可怕的怪物是半人半獸)
- William is half Russian, half French. (威廉有一半俄羅斯血統，一半法國血統)
Half 當副詞用：
- William spoke half in Russian and half in French. (威廉一半講俄語，一半講法語)
- Her husband was only half awake. (她先生只是半醒)
- Through the half open door I could hear the background noise. (從半開的門我可以聽到背景雜音)
- The students only half understood what Professor Tsai was saying. (蔡教授所說的話，學生只聽懂一半)
- The rocks were half under water. (礁石有一部份在水下)
最後要談的是「多一半」的英文，那就是 “half as + many, much 或其他形容詞 + again (+ as)” 或 “half again + as + many, much 或其他形容詞 (+ as)”。事實上，中文的「多一半」與「多一倍半」是一樣的，前者是「某數 + 某數的二分之一」(如 6 + 3 = 9)，後者是「某數 x 1.5」(如 6 x 1.5 = 9)。例如：
- An apartment in Kaohsiung costs half as much again as (or half again as much as) a similar apartment in Pingtung. (在高雄買一間公寓比在屏東買同樣一間公寓要多花一半的錢)
- The company’s exports to Asia are half as many again as (or half again as many as) those to Europe. (這家公司對亞洲的出口是對歐洲出口的一倍半)
這裡還有一篇有關 Half 的用法說明，歡迎參閱。