have與has都是“有”的意思，但二者用法是有區(qū)別的。
在陳述句中，當(dāng)主語(yǔ)是單數(shù)第三人稱（he、she、it）時(shí)，句子的謂語(yǔ)是“有”時(shí)，用has；當(dāng)主語(yǔ)是其他人稱（I、you、we、they）時(shí)，句子的謂語(yǔ)是“有”時(shí)，用have。
例句：
I You have an apple .
WeThey have some apples .
HeShe has a pen .
但是，在疑問(wèn)句中，當(dāng)主語(yǔ)是就單數(shù)第三人稱提問(wèn)或否定句時(shí)用助動(dòng)詞does 和does not (doesn't)，然后把has 變成have 如果不是第三人稱,助動(dòng)詞就是do ,否定式do not (don't).特殊疑問(wèn)句回答照樣,該是has 還是has 該是have 還是have 但是當(dāng)一般疑問(wèn)句 以do或does開(kāi)頭的時(shí)候,只能回答 do dont 或者 does doesn't
例句：
Do you have a book ? yes ,I do /No , I don't
What does a cat have ? the cat has a ,,,,,,,
He doesnt have any coffee.
have本身也可以作為助動(dòng)詞，(作為完成時(shí)里的助動(dòng)詞)本身無(wú)詞義，和do 一樣,has 就相當(dāng)于does 在單三情況下用, 主要用于構(gòu)成各種時(shí)態(tài)、語(yǔ)態(tài)、語(yǔ)氣以及否定和疑問(wèn)結(jié)構(gòu)。（那此時(shí)的have還是has就要看具體的人稱而定）完成時(shí)態(tài)是have/had + done (過(guò)去分詞的形式)
I have finished my work, she has finished her work
have you finished your work? has she finished her work? 在一般疑問(wèn)句里回答直接用have/has
yes,i have/ No , i haven't Yes, she has/ No, she hasn't(因?yàn)檫@里have/has是助動(dòng)詞)