介系詞 at 跟 in

如果以地方大小來區別 那麼我們就很難理解為什麼搭飛機時 機長廣播: We'll be making a short intermediary stop at Tokyo. 東京明明是大城市 怎麼用at?

兩字的差別除了空間因素 還有活動型態

AT:
1. 地圖上的某個點 例如 The bank is at No. 10 Park Road.
2. 路線上經過的一站 例如 This is the express train from Taipei to Hualien. There are three stops at Keelung, Yilan, and Luotung.

IN:
1. 強調inside 例如 It is freezing cold out there. I'll wait in the library.
2. 表可供人活動的三度空間 例如 HUndreds of thousands of people commute to and from Taipei every day. They work or go to school in this largest city in Taiwan.


AT HOME/SCHOOL 表示地圖上的點
不過慣用片語 AT SCHOOL或IN SCHOOL也可以表示"在學中; 還是學生身分"

至於有沒有可能AT THE PARK? 當然可能: Our flagship store is located at the 228 Peace Park. 我們的旗艦店位於228和平公園附近

希望有助於解您的惑

We say like that I was at home or I was at school yesterday

or I was in the park, say things like these which make sense,

But what is the difference between at school and in school?

at school means you were there.

in school means you were not really over there, for example: I used to be brilliant when I was in school.

介係詞真的很難。只能憑語感，但你列出來 at 非常好，「特定地點」，at home、at school 、at the mall，都是在一個特定地點，不管大小。

in the park 也不要用大地方、小地方來感覺，in 有指「四周圍起來」的地點之中，或「一個範圍內」之中。所以用 in the park 是表示在公園的範圍內，或圈圈內。

你也可以用 at the park 或 in school 但意思就不同了。

in the park 是公園內。但很多旅館、酒店都在大公園附近，他們取名都加一個，「某某 at the park」表示很好認的公園旁的那間，這時 park 是特定地點的感覺。

at school 是「在學校」指特定地點，in school 是「在學」，指學生註冊念書。

She is at school now.
她現在（人在）在學校。

She is in school now.
她現在回學校當學生了。（她現在是學生了。）（她現在上學了。）

When I was in school, PE was required.
我在學念書的時候，體育是必修課。


所以用大地方、小地方來分 at 和 in 有困擾，用「範圍內」和特定地點來感覺，比較好。例如 town 可能比 city 小，但 in the town 和 in the city 同樣用 in。 而 home 比 mall 小，但 at home 和 at the mall 都用 at。