英汉词典

1. 介词；前置词
    A preposition is a word such as 'by', 'for', 'into', or 'with' which usually has a noun group as its object.

    e.g. There is nothing in the rules of grammar to suggest that ending a sentence with a preposition is wrong.
           语法规则中并没有规定句子以介词结尾是错误的。