happened on:偶然遇到或发现 He happened on the book in an secondhand bookstore. 他碰巧在一家旧书店里发现了这本书. happened with: About what happened with us.我们之间的事 Things finally happened with Kate.我跟凯特终于有进展了 happened to:发生于;偶然发生 Let me tell you what happened to me once. 让我告诉你曾经发生在我身上的事. happened for : That's kind of how it happened for Andrew. 这就类似在安德鲁(拜纳姆)身上所发生的. In books this has already happened for encyclopedias. 对于百科全书来说,这一变化已经来临了.