Definition: If something is useless, it does not work well or it has no effect. Level: B1
这把伞没用了——上面有个大洞。
This umbrella's ___useless - there's a big hole in it.
跟她争论是没用的。
It's ___useless arguing with her.
我开始挖掘，但那是徒劳的。
I started digging, but it was ___useless.
