用作定语
▲～+n.
He's a useless fellow.他是个没用的家伙。
用作表语
▲S+be+～
This new secretary is useless and must be dismissed at once.这位新来的秘书真没用,得马上辞退。
This method of working is useless.这样做没成功的希望。
▲S+be+～+prep.-phrase
He is useless at maths.他的数学不好。
His advise is useless to our project.他的建议对我们的计划没有什么价值。
A car is useless without gasoline.汽车没有汽油便无用。
