1. 复数的；复数形式的
    The plural form of a word is the form that is used when referring to more than one person or thing.

    e.g. 'Data' is the Latin plural form of 'datum'.
           data 在拉丁文中是 datum 的复数形式。
    e.g. ...his use of the plural pronoun 'we'.
           他对复数代词 we 的使用

2. 复数；复数形式
    The plural of a noun is the form of it that is used to refer to more than one person or thing.

    e.g. What is the plural of 'person'?
           person 的复数形式是什么？
    e.g. ...irregular plurals.
           不规则复数形式

3. 多元的；多种群体的
    A plural society or system involves different kinds of people.

    e.g. Britain is a plural society in which the secular predominates...
           英国是个世俗主导的多元社会。
    e.g. His government has pledged to move the country towards a plural democracy.
           他的政府已承诺要推动本国朝着多元民主的方向发展。