## 用一下兒

In this phrase, 用 is a verb which can be used both transitively and
intransitively (i.e. it can be used either with or without an object).
一下兒 is an adverbial of time indicating "a short while, a little
while". If an object is to be used for 用 in the above phrase, it should
be placed after 一下兒:

    我用一下兒你的書﹐好嗎﹖
        Is it all right for me to use your book for a short while?
    他們用一下兒你爸爸的車。
        They want to use your dad's car for a little while.