but是連詞,表示（較強的）轉(zhuǎn)折,連接兩個句子時只用加逗號.例如：I love her,but she doesn't love me.
however是副詞,也表示（較強的)轉(zhuǎn)折,但連接兩個句子時要用分號,而且在這個詞后還要加逗號.例如：I love her; however,she doesn't love me.或者將兩句子分開寫.例如：I love her.However,she doesn't love me.
while作連詞使用時,表示（較弱的）轉(zhuǎn)折,連接兩個句子時用逗號,但兩個句子的主語不一樣.例如:I like singing,while my sister likes dancing.
yet作連詞使用時,也表示（較弱的）轉(zhuǎn)折,連接兩個句子時也用逗號,但兩個句子的主語是一樣的.例如：He has a good job,yet he never seems o have any money.