Which is an English word that functions as:
1. An interrogative pronoun: "Which one do you prefer?"
2. A relative pronoun: "The book which I bought yesterday is interesting."
3. A determiner: "Which way should we go?"
4. In non-defining clauses: "My car, which is red, is parked outside."
which这个英文单词可太常见了，咱们来掰扯掰扯它的用法：
1. 疑问代词："哪个你更喜欢啊？"（Which one do you prefer?）
2. 关系代词："我昨天买的那本书可有意思了。"（The book which I bought yesterday is interesting.）
3. 限定词："咱们该走哪条道儿啊？"（Which way should we go?）
4. 非限定性从句："我那辆红色的车，就停在外面。"（My car, which is red, is parked outside.）
补充说明：which和that的区别可得注意咯，非限定性从句只能用which，不能用that。这玩意儿在英语考试里可是高频考点，可得整明白喽！