this evening是指今天晚上的早些时候，tonight是指今天的整个晚上包括深夜。this evening在时间上要早一些。例句：Let's go out this evening.I thought we could go out tonight.
this evening双语例句1.Will she cook dinner this evening?
她今晚要做晚饭吗？
2.Have we got anything (ie any engagements,plans,etc) on for this evening?
今天晚上我们有什麽安排吗?
3.Our new serial thriller begins at 7.30 this evening.
我们的新系列惊险故事于今晚7时30分开始播出。
tonight双语例句1.I'd like to take you out to dinner tonight.
今天晚上我想带你出去吃饭。
2.Now for a summary of tonight's main news stories.
现在是今晚主要新闻综述。
3.It may freeze tonight, so bring those plants inside.
今夜可能有霜冻，把花草搬进屋来吧。
