Same 可當形容詞和代名詞用，前者意為「同一的；相同的；一樣的」，後者意為「相同的人；相同的事物」，指的是兩個或多個人事物完全相同。當我們使用 same 來比較人事物時，其前須有定冠詞 the。例如：
- John and I went to the same school. (約翰和我曾在同一所學校唸書) (正)
John and I went to same school. (誤) - These two tables are not the same. (這兩張桌子並不一樣) (正)
These two tables are not same. (誤)
The same as
The same 後面是接 as 不是 that 或 than。例如：
- I treat daughters exactly the same as sons. (我對女兒和兒子完全一視同仁) (正)
I treat daughters exactly the same that sons. (誤)
I treat daughters exactly the same than sons. (誤) - My new jacket is the same model as my old one. (我新外套的款式與舊外套一樣) (正)
My new jacket is the same model that my old one. (誤)
My new jacket is the same model than my old one. (誤)
The same + 名詞 + 子句
當 the same 與名詞連用時，其後可接 that 引導的關係子句，亦可接比較少用的 who 或 which 引導的關係子句。但我們通常省略這些關係代名詞。例如：
- He’s the same person (that) John fought with at that restaurant last night. (他是昨晚在那家餐廳和約翰打架的人)
- Is Linda still going out with the same boyfriend (who) we knew when we were at college? (琳達還在和我們唸大學時認識的同一個男朋友交往嗎？)
我們經常在 the same 前面使用 exactly/just、much 和 very 等副詞來修飾或加強語氣，但它們所在的位置並不完全相同。Exactly/just和 much 係位在 the same 的前面，即 exactly/just the same (完全一樣的；一模一樣的)、much the same (= almost the same) (幾乎一樣的；幾乎一模一樣的)，而 very 係位在 the 和 same 之間，即 the very same (正是同一個)。例如：
- Mary was wearing exactly/just the same skirt as I was. (瑪麗所穿的裙子和我的一模一樣)
- My opinion on this subject was much the same as theirs. (我對這一主題的看法與他們幾乎一樣)
- It was the very same day that my grandfather died. (那正好是我祖父過世的同一天)
- That very same day, he got married and died in a car accident. (就在同一天，他結婚並在車禍中喪生)
Similar 和 identical
Similar 和 identical 這兩個形容詞分別意為「相似的，相像的，類似的」和「同一的，完全相同的」。它們的句型為 similar to、a similar + 名詞或 a similar + one 以及 identical to、an identical + 名詞或 an identical + one。我們不可使用 a same。例如：
- My purse is similar to yours. (我的錢包和你的相似)
- We had a similar problem, so the solution could be the same. (我們有類似的問題，所以解決辦法可能是一樣的) (正)
We had a same problem, so the solution could be the same. (誤) - His bicycle is identical to mine. (他的腳踏車和我的一模一樣)
- These two words are identical in pronunciation. (這兩個字的發音完全一樣)
- The salesclerk first showed me a red skirt. Then she showed me an identical one, but they were produced by two different companies. (店員先讓我看一件紅裙。然後她又讓我看一件完全一樣的紅裙，但它們是由兩家不同的公司所生產) (正)
The salesclerk first showed me a red skirt. Then she showed me a same one, but they were produced by two different companies. (誤)