Alike 可用作形容詞和副詞，當形容詞用時意為「相似的，類似的；相像的」。例如：
- The twins look very much alike. (這對雙胞胎長得非常相像)
- They are not brothers but their clothes are alike, aren’t they? (他們不是兄弟，但他們的衣服很相似，不是嗎？)
Alike 當形容詞用時只能放在 be、seem 和 look 等連綴動詞的後面，不可用作定語形容詞 (attributive adjective) 放在名詞的前面；換言之，它只能用作表語形容詞 (predicative adjective)。例如：
- The two girls, who looked alike, sat silently in the corner. (兩個長得很像的女孩默默地坐在角落裡) (正)
- The two alike girls sat silently in the corner. (誤)
Alike 當副詞用時意為「相似地；相同地」。例如：
- The twins even dress alike. (這對雙胞胎就連衣著都一樣)
- The boss treats us all alike. (老闆對我們都一視同仁)
當副詞用的 alike 還意為「同樣地，同等地；兩者都」。例如：
- Family and friends alike were devastated by the news of his death. (他的家人和朋友都對他過世的噩耗感到悲痛欲絕)
值得注意的是，alike 不可用作介系詞來表示相像、相似的意思，此時必須使用 like。例如：
- I’ve got a skirt just like that. (我有一件和那件一模一樣的裙子) (正)
I’ve got a skirt just alike that. (誤) - She’s very much like her mother. (她和她母親非常像) (正)
She’s very much alike her mother. (誤)