同位」(apposition) 指「名詞或名詞相等語」與其他的「名詞或名詞相等語」並列,以充作補充說明之用,這樣的關係即稱為「同位」。「同位」可以分成下列幾種類型:

(1) 「名詞+名詞」

Mr. Huang, our new teacher, teaches us English.
    (
黃先生是我們的新老師,教我們英文。)
    <our new teacher
Mr. Huang 的同位語>

Baseball, his favorite sport, has brought him a lot of good friends.
    (
棒球是他最喜歡的運動,讓他交到許多好朋友。)
    <his favorite sport
Baseball 的同位語 >

President Kennedy was assassinated in 1963.
    (
甘迺迪總統於1963年被暗殺。)
    <Kennedy
President 的同位語>

(2) 「代名詞+名詞」

We Taiwanese live on rice.
    (我們台灣人以米為主食。)
   
<Taiwanese We 的同位語>

The hope of Taiwan lies in you young men.
    (台灣的希望就要靠你們年青人。)
   
<young men you 的同位語>

(3) 「名詞+名詞子句」

Is there any proof that the gun was his?
    (可有任何證據指出這把槍是他的?)
    <that the gun was his 為 proof 的同位語>

The fact that he was dead made no particular difference to her.
    (他死掉這件事對她來講不關痛癢。)
    <that he was dead 是 fact 的同位語>

The question whether he should have an operation or not troubled him. (該不該動手術這個問題困擾著他。) <whether he should have an operation or not 為 question 的同位語>

(4) 「句子+名詞」

The summer continued hot and dry, a condition which gave rise to the danger of forest fires. (該夏季一直又熱又乾,這種情況有發生森林火災的危險。) <a condition 為"The summer continued hot and dry"這個句子的同位語>

Naturally I left the letter unansweredthe only way to keep myself from their company. (我當然不予回信,這是我跟他們斷絕關係的唯一辦法。) <the only way 為"Naturally I left the letter unanswered"這個句子的同位語>

(5) 「名詞+of+名詞」

此一 of 用於表示「叫作~」或「像~似的」之意。

(a) 「叫作~」

the city of London (叫作倫敦的城市→即倫敦市)

his habit of smoking (他的抽煙習慣)

(b) 「像~似的」<名詞+of a+名詞>:這是充滿感情的說法,前半的 <名詞+of> 係扮演後面的名詞的形容詞的角色。

an angel of a girl = a girl like an angel (天使般的女孩)

this jewel of an island (這個寶石般的島嶼)