Question

关于has had或have had的用法

如题. 有一次去看医生,得了流感
我跟医生说 i have flu
医生问 how long have you had it for?
然后我的问题是，为什么医生不问 have long have you been having it for? 就是为什么不用been having,而用have had??

然后另一个相似问题,卖家在ebay上卖架电脑, 描述是 i`ve had it for a year
为什么不用 i have it for a year或i have been having it for a year???

不确定的别回答了, 不想被误导 因为已经很confused了.. :)
hmmmm 半理解半不理解 但首先谢谢你指教
这么问吧，以下分别哪些情况用哪句？为什么？
He has been having an affair for years
He has had an affair for years

He has run the business for years
He has been running the business for years

He has been coughing for years
He has had a/the cough for years

Answer 1

同学， 我个人理解是 得病这个动作 是一瞬间的，你没有办法一直“得”病，所以用had，表示过去已经发生的。