Our teacher 【is】 cating breakfast.第三人称单数,用is
Are 【you】 cleaning the room?你的主格
I am 【not】 swimming.not
What is John 【doing】?现在进行时
She's writing 【an】 e-mail.an
I am working 【on】 the computer.
She often 【cleans】 the room.第三人称单数
Our teacher 【is】 cating breakfast.第三人称单数,用is
Are 【you】 cleaning the room?你的主格
I am 【not】 swimming.not
What is John 【doing】?现在进行时
She's writing 【an】 e-mail.an
I am working 【on】 the computer.
She often 【cleans】 the room.第三人称单数