No, that's not true. See the following example.I heard from a friend that に is used when the event happens repeatedly, is it true?
As a native English speaker, I don't believe so.Doesn't "に is used when the event happens repeatedly" connote that "に is not used when the event doesn't happen repeatedly" in this context? Anyway, "whether the event happens repeatedly or not" has nothing to do with the use of に.
There is no problem to use は twice in a single sentence. The following thread is exactly regarding this topic.could I say 美術館は週末に5時に閉館します/終わります if I'm making the museum the primary subject? Or would it be more natural to say 週末は5時に閉館します, and focus specifically on the "weekend"? Could I also double up the は particles and still say "美術館は" before the second sentence? I generally try to avoid using it twice in a sentence