"for" 是一个多功能的英语词汇，它可以用作介词或连词。当它作为介词时，后面通常需要跟 名词、代词、动名词或动名词短语。例如：
1. She is looking for a new job.
2. They are playing football for the team.
3. This gift is for you.
4. I bought this book for you.
当 "for" 作为连词时，后面跟的是一个句子，通常用来表示原因或目的。例如：
1. I stayed at home for the entire weekend.
2. She studied hard for the exam.
因此，"for" 后面可以跟的词性包括名词、代词、动名词或动名词短语，具体使用哪种词性取决于句子的语境和所要表达的意义。