首先根據(jù)后面的回答I have never seen him before說(shuō)明他確實(shí)不是他的一個(gè)朋友,所以確定應(yīng)該是no,這兒也叫做假戲真做,其次反問(wèn)句為is he?所以回答應(yīng)該和其相反所以應(yīng)該是he isn't ,這類(lèi)題都有這個(gè)規(guī)律,也可以這樣理He is not a friend of yours,is he?可以理解為 He is not a friend of yours,is he not a friend of yours?也就是問(wèn)他不是你的一個(gè)朋友,他是嗎?根據(jù)后面的回答確定不是應(yīng)該為no,他不是（he isn't）,這類(lèi)題就是這個(gè)規(guī)律,除了反問(wèn)詞為幾個(gè)特殊的疑問(wèn)詞,這一點(diǎn)隨便這個(gè)語(yǔ)法書(shū)上面都會(huì)有介紹,希望對(duì)你有用!