高考英语核心词but和however的区别

But 和 however 都表示“但是”，核心区别就三点：词性不同、位置不同、正式程度不同。

词性不同是最根本的区别。

But 是连词，它的任务是把前后两个分句粘在一起，所以 but 出现的地方，前后一定各有一个完整的句子。比如：I like tea, but I don't like coffee。

However 是副词，它不能像胶水一样连接两个分句，它更像是一个路标，需要被逗号或分号隔开。比如：However, I don't like coffee。或者：I like tea; however, I don't like coffee。

位置不同。

But 比较死板，只能待在两个分句中间。比如：I wanted to go, but I was too tired。写作中不建议把 but 放在句首直接连接两个完整句子。However 位置很灵活，句首、句中、句尾都能放。比如句首：However, the results were not significant。句中：The results were significant; however, the sample size was small。句尾较少用：I don't like coffee. I drink it every morning, however。

正式程度不同。

But 口语、日常写作、邮件、故事里都很自然，直接干脆。

However 转折语气更重，常见于论文、报告、正式邮件，给人一种慎重转折的感觉。口语里你会说：I wanted to go, but I was too tired。论文里会写：The treatment was effective; however, side effects were observed。

最容易踩的坑有两个。

第一，however 不能直接连接两个分句。

错误写法：I like tea, however I don't like coffee。

正确写法：I like tea; however, I don't like coffee。或者：However, I don't like coffee。

第二，but 前面要有逗号，不是随便贴上去的。

错误写法：I was late but she left。

正确写法：I was late, but she left。

简单记一句话就够：

But 是胶水，粘连前后句；however 是路标，要与句隔开。

选择最合适的词填空（but / however）：

1. She studied hard, ___ she didn't pass the exam.

2. ___ , she didn't pass the exam although she studied hard.

3. She studied hard; ___, she didn't pass the exam.

4. He is very rich. He is ，___， not happy.

5. I wanted to call you last night ，___ I forgot your number.

———答案与解析———

1. but （连接两个分句，用连词 but）

2. However （句首，用副词 however，后接逗号）

3. however （分号后接副词 however，后加逗号）

4. however （插入句中作副词，表示“然而、却”：He is very rich. He is, however, not happy. 也可写 He is very rich; he is, however, not happy. 简写 He is very rich but not happy.）

5. but （连接分句，用连词）