1、单词、短语和从句均可充当同位语，对单词作同位语来说，名词、数词、代词和形容词均可作同位语，如he read all kinds of books, ancient and modern, Chinese and foreign
2、对短语作同位语来说，名词短语，动名词短语，不定式短语以及介词短语均可作同位语，如She likes her job, teaching English
3、Wang Li, just back from the trainning class, was made director of the department. 其中just back from the training class是Wang Li的同位语
4、作同位语的从句又叫同位语从句，同位语从句一般跟在表示抽象概念的名词后面，用以说明该词所表示的具体内容。这些名词包括：news, idea, fact, question, thought, hope, message, suggestion等等
5、He told me the news that the plane had exploded，其中，the plane had exploded是news的同位语
6、同位语通常伴有标志词，以表示与它所解释说明的词之间的关系，如namely, that is to say, in other words表等同关系，for example, for instance, such as表列举关系，especially, particularly等表示突出某一点，等等
