A給了B一支筆，C說“Why would you give her a pen?”這里為何不直接說“Why did you give her a pen.”

would 表示情態(tài)意義，含有“想那樣做” 之意，對(duì)于一個(gè)過去已經(jīng)推行了的動(dòng)作，可以用 would，指當(dāng)時(shí)想那樣做。網(wǎng)友的句子便是。

“Why would you give her a pen?”

這句話的意思是：“你為何要給她一支筆呢？”（在做過之后問，詢問想給是什么原因）

“Why did you give her a pen.”

這句話的意思是：“你為何給她一支筆呢？”（也是在做過之后問，只問動(dòng)作是什么原因，不含情態(tài)意義）