I haven't it.

该句中have为实义动词，其否定形式应为don't have
正确的说法为：I don't have it.

haven't 加动词短句
后面名词 要用 don't have
I don't have it

口语中这句是可以的 要改的话可以是I haven't got it.很多意思了没有完成，没拿到等等。。。楼上的也可以这样改不过感觉缺少点什么。。。太死板了- -