but things got so bad recently that he decided to go on a diet 这里的go on a 是短语吗

题目

but things got so bad recently that he decided to go on a diet 这里的go on a 是短语吗

答案

这里 go on 是 embark on 的意思,不是 continue 的意思.
类似的句子：
go on a shopping spree
go on a rampage
go on a wild goose chase