英语五大变形句包括：

主语从句

示例：That Mary likes eating vegetables is very obvious.

解析：“That Mary likes eating vegetables”作主语，是由引导词that引导的主语从句。

宾语从句

示例：I know Mary likes eating vegetables.

解析：“Mary likes eating vegetables”作“I know”的宾语，故宾语从句。

表语从句

示例：The most important thing is （that） Mary likes eating vegetables.

解析：“（that） Mary likes eating vegetables”作“The most important thing”的表语，故表语从句。

倒装句

示例：Here comes the bus!

解析：正常语序为“The bus is coming here.”，倒装句将谓语动词“comes”放在主语“the bus”前面，用于强调或表示惊讶。

强调句

示例：Only when I arrived at the party did I realize how late it was.

解析：将强调部分“Only when I arrived at the party”放在句首，用以强调该部分的重要性。

这些变形句在英语中非常常见，掌握它们有助于提高英语表达的准确性和流畅性。