在英语中，定语从句是一种常用的修饰语句型，用于修饰一个名词或代词。在定语从句中，引导词的位置常常是令人困惑的问题。
英语中，定语从句的引导词有：that, which, who, whom, whose, where, when等。这些引导词在定语从句中的位置有所不同，有些出现在句首，有些出现在句中，有些出现在句尾。
- that
that是最常用的定语从句引导词，它可以出现在句首、句中和句尾。
例如：
- The book that I bought yesterday is very interesting.
- I have a friend who/that lives in New York.
- Do you remember the day when we met each other?
- which
which一般出现在句中或句尾，用来修饰事物。
例如：
- The car, which is very expensive, belongs to my boss.
- This is the book which I have been looking for.
需要注意的是，which不能用来修饰人，只能用来修饰事物。
- who/whom
who/whom用来修饰人，who一般出现在句中或句尾，而whom一般出现在句尾。
例如：
- The girl who/whom you met yesterday is my sister.
- The man who/whom we are talking about is a famous actor.
需要注意的是，who用来指代主语，而whom用来指代宾语。
- whose
whose用来修饰名词，表示所属关系，一般出现在句中或句尾。
例如：
- The boy whose father is a doctor is my classmate.
- This is the house whose roof was damaged in the storm.
- where
where用来修饰地点，通常出现在句中或句尾。
例如：
- This is the school where I studied when I was young.
- Can you tell me the place where we can buy some food?
- when
when用来修饰时间，通常出现在句中或句尾。
例如：
- The year when we graduated from college was 2010.
- This is the day when we will celebrate our anniversary.
以上是关于定语从句引导词位置的介绍，希望对大家有所帮助。记住，在写定语从句时，要根据引导词的不同位置，来选择正确的语法结构和单词顺序。
