1)主格人称代词要变成相应的复数主格人称代词,即I→we, you→you，she,he,it→ they。如：
She is a girl. →They are girls.
(2)am，is要变为are。如：
I’m a student. →We are students.
(3)不定冠词a，an要去掉。如：
He is a boy. →They are boys.
(4)普通单数名词要变为复数形式。如：
It is an apple. →They are apples.
(5)指示代词this，that要变为these，those。如：
This is a box. →These are boxes.
