The existence and common use of 然而 highlight the distinction between written language (书面语, shūmiànyǔ) and spoken language (口语, kǒuyǔ) in Chinese. This distinction is often more pronounced than in modern English. Using a word like 然而 in writing or formal speech is a sign of education and demonstrates respect for the formality of the situation. In Western culture, the difference between “but” and “however” is mainly about register. In Chinese, the choice between 但是 (dànshì) and 然而 (rán'ér) is similar but also tied to the context of communication itself—is it a casual conversation or a structured, formal discourse? The use of 然而 reflects a cultural appreciation for well-structured, logical arguments, especially in academic, political, and business contexts. It's a tool for building a careful, considered point, rather than just stating a simple contradiction.
The connotation of 然而 is neutral; it is a logical connector. Its formality level, however, is high.
The most common mistake for learners is using 然而 when they should use 但是 (dànshì) or 可是 (kěshì). It's grammatically correct but sounds unnatural and overly formal, as if you're giving a speech to a friend.