本来跟devote 搭配的to 就是介词啊,结构一般是 devote to sth/doing sth.
eg：He devoted himself to his career.他全身心投入他的事业中.
Leifeng has devoted his whole life to helping others.雷锋一生都乐于助人.这种判断是介词还是不定式必须是要背诵的么？还是有什么方法？要记住才行，没有其他方法的。这类的to作介词的词组并不多，常用的还有look forward to，pay attention to等