将英语定语从句转换为简单句，可以通过以下几种方法：

省略关系词

如果定语从句中的关系词在从句中作宾语，可以省略关系词。例如：

The man who you met just now is my father.

The books which lie under the bed aren't worth reading.

将定语从句转换为形容词短语

将定语从句中的关系代词或关系副词替换为相应的形容词或形容词短语。例如：

The man talking over there is my brother.

This is a book that is worth reading.

将定语从句转换为介词短语

将定语从句中的关系代词或关系副词替换为相应的介词短语。例如：

The man who you're talking to is my friend.

The engineer, whose leg was badly hurt, was quickly sent to hospital.

将定语从句转换为不定式或不定式短语

将定语从句中的关系代词或关系副词替换为相应的不定式或不定式短语。例如：

Have you anything that you want to say at the meeting？

Do you know the gentleman who/that is sitting there？

将定语从句拆分为两个简单句

将定语从句拆分为两个独立的简单句，用并列连词连接。例如：

I like music that I can dance to.

The musician who is performing on the stage comes from Australia.

通过以上方法，可以将复杂的定语从句转换为简单句，使句子更加简洁明了。