表达悲伤失望情绪的英语口语

白费力了.

***It was a waste of effort.

*waste "浪费"、"白搭",effort表示"努力"、"费尽力气".

My effort was wasted.

***All my effort went down the drain. 白费劲.

*(go) down the drain:(to be) wasted; (to get) very much worse 被浪费掉;变得非常糟糕
It's just money down the drain, you know. 你要知道.这是白白丢钱.
Safety standards have gone down the drain. 安全标准根本不管用了.
提示:如果在口语中能偶尔用上这个短语的话,还是很出彩的.

***a wild-goose chase

*wild goose表示"过路的大雁",chase意为"追赶".会话中常用.

Did you find him. (你找到他了吗?)

No, he led me on a wild-goose chase. (没有,白费了半天劲.)