•Without fuel, the vehicles will become useless for moving supplies.没有燃料，车辆就无法运送物资。

•[+ to infinitive] It's useless to speculate without more information.没有更多资讯，推断毫无意义。

•She's very good at methodical work, but useless when there's a lot of pressure.她很善于做条理性强的工作，但要是压力太大她就做不来了。

•informal You're absolutely useless (= not able to act effectively) - can't you even go to the shops without getting lost!你真没用——连去商店买东西都会迷路！