⋯⋯， 然而⋯⋯
Explanation
“然而”表示转折关系，连接前后意思相反或相对的分句，语气比“但是”稍显正式，常用于书面语或较正式的口语表达。
However is used to express a contrast or contradiction between two clauses, similar to 'but' but slightly more formal, often used in written language or formal speech.
Examples
我知道中文很有用，然而中文也太难了。
I know Chinese is very useful, however, Chinese is also too difficult.
他说他不喜欢这部电影，然而我觉得很有意思。
He said he didn't like this movie, however, I think it's very interesting.