介词后面可以接宾语,因此分析问题要从什么词可以做宾语开始:
He is looking at me.(代词可放在介词后面)
We need to take care of the old.(the +形容词 可放介词后)
He is thinking about what they are doing now.(宾语从句可放在介词后)
等等
所以除了你所说的可以接动名词和名词,还可用其他词。
所谓的介词,就是用在名词或代词的后面说明这个名词或代词与句中其他词的关系的词。他后面只能接名词或代词,如果是动作通常要改为动名词。如:
He is good at writing.他擅长书写。
Thanks for helping me.或Thanks for your help.谢谢你的帮助。