tonight是指今天的整个晚上包括深夜，表示“今晚”的含义。this evening是指今天晚上的早些时候，表示“今天傍晚”的含义，this evening表达的意思比tonight在时间上要早一些。
tonight例句I thought we could go out tonight.
我本想我们今晚可以出去。
I'd like to book a table for two for 8 o'clock tonight.
我想订一张今晚8点钟的二人餐桌。
I'd like to take you out to dinner tonight.
今天晚上我想带你出去吃饭。
Now for a summary of tonight's main news stories.
现在是今晚主要新闻综述。
It may freeze tonight, so bring those plants inside.
今夜可能有霜冻，把花草搬进屋来吧。
this evening例句Let's go out this evening.
咱们今天晚上出去吧。
You have a point ─ it would be better to wait till this evening.
你说的有道理，还是等到今天晚上比较好。
It's nice to see some new faces here this evening.
今晚在这儿见到一些新面孔真是太好了。
I'm having people to dinner this evening.
今晚我在家里宴请客人。
Take extra care on the roads this evening.
今晚在路上要格外小心。
