言うでもない;-は言うまでなく,-も
文法の解説は英語です。
用法
This phrase is used when the speaker mentions something obvious or something assumed to be known to the hearer. It is commonly used in written language. Needless to say; It goes without saying that; It is obvious that -;
例文
明日の試験では、言うまでもなく、文法の問題が出ます。
The test tomorrow, it is obvious that there will be questions related to grammar.
図書館では静かにしなくてはいけないことは、言うまでもない。
It goes without saying that inside of the library that being quiet is necessary.