非限制性同位语是英语中一种常见的修辞结构。它通常用来为名词或名词短语提供额外的信息，但不是必需的。非限制性同位语通常用逗号将其与主句分开。
名词(短语)充当同位语用来提供补充信息
- Mr. Smith, our new teacher, is very kind to us. 我们的新老师史密斯先生对我们很好。
- Beijing, the capital city of China, is located in the north. 北京，中国的首都，位于北方。
- The train finally arrived and two young men — one big and broad，the other small and slight — stepped onto the platform. 火车终于到站，两位年轻人 —— 一位大个儿，体格魁梧；另一位，小个儿，长相瘦弱 —— 踏上了月台。
- They have everything they need: land, brains, wealth and technology. 他们有他们需要的一切：土地，人才，财富和枝术。
- He collected various old items at the flea market, old books, vintage toys, and rare playing cards.（他在跳蚤市场收集了各种老物品，旧书、复古玩具和稀有扑克牌。）
有些副词、代词、插入语，专门用于引导同位语来提供进一步解释
- He excels in various subjects, namely mathematics, science, and computer programming.（他在多个科目中表现出色，即数学、科学和计算机编程。）
- Some students, for example, John, live in the city. 有些学生，例如约翰吧，就住在城里。
- He is interested in sports, especially ball games. 他喜欢运动,特别是球类运动。
- She has a wide range of interests, that is, art, music, and literature.（她兴趣广泛，也就是她热衷于艺术、音乐和文学。）
- More than 20 people were killed, including five policemen. 超过20人丧生，其中包括5名警察。
形容词充当非限制性同位语
- All the countries，big or small，are equal. 所有的国家，不分大小, 都是平等的。
- He has read all kinds of books, ancient and modern, Chinese and foreign. 他看了各种和样的书，古今中外都有。
- He read all kinds of books, ancient and modem, Chinese and foreign. 他博览群书，古今中外都有。
- The middle-aged man is a newly elected team leader, able, open, and sincere. 那位中年 人是新当选的队长，他能干，开明，真诚。
- The weather, unpredictable and windy, can make outdoor plans challenging.（天气，变幻莫测并且有风，可能会使户外计划变得具有挑战性。）
同位语可以提前， 特别是主语比较短时，用于突出同位语
- Two grain crops a year-rice and wheat- are grown on most of the land. 大部分土地一年有两季收成，一季水稻，一季小麦。
- Only one problem still remains——the storage of the grain. 只剩下一个问题，那就是粮食储存。
- A person of French origin，he is now an American citizen. 他的籍贯在法国，但他现在是美国公民。
- Formerly a worker himself, he is now an engineer. 他过去是工人，现在是一名工程师了。
- Air, food, water and heat-these are four requirements of all living things. 空气、食物、水和热源，这些是所有生物的四大必需品。