`for` 是一个介词，在英语中，介词后面通常跟名词、代词、动名词（动词的ing形式）或者动名词短语。以下是`for`后面可以跟的一些词类及其例句：
1. 名词
例句：The book is for my brother.
2. 代词（宾格形式）
例句：You can ask me anything for help.
3. 动名词（V-ing形式）
例句：He is thinking for a solution.
4. 动名词短语
例句：We should search the room for evidence.
5. 时间
例句：For the time being, it's business as usual.
6. 原因
例句：He is doing this just for you.
7. 目的
例句：A good dictionary is indispensable for learning a foreign language.
8. 对象
例句：These books are for my brother.
9. 用途
例句：The pen is used for writing.
10. 范围
例句：For example, you can use a for loop in programming.
请根据您想表达的具体意思选择合适的词类跟随`for`