Ⅰ. at school表示“在學校、在上學”相對于在家里或在校外。如：

　　① My son is at school now. He is not at home or somewhere else. 我兒子現在在學校，他不在家，也不在別的地方。

　?、?When my brother was at school, he studied very hard. 在學校時，我兄弟學習很用功。

　　Ⅱ. in school “在求學、在上學”相對于有工作。如：

　　My daughter still in school She doesn’t work.。 我女兒還在上學，她不在工作。

　?。孩俸廷谟胊t school 強調所在場所或時間。③中的in school 則強調主語的身份是學生。因此，in school. 和 at school的著重點不一樣，通常不互換使用。

　　Ⅲ. In a / the school “在學校”，不一定指上學。類似的還有：

　　in hospital “生病住院”

　　in a / the hospital表“在醫院”(工作或探視病人等)

　　at table “在吃飯”

　　at a / the table “在桌邊”(有可能在聊天或看報)

　　① Is your friend in school? 你的朋友在上學嗎?

　?、?Your friend looked for you in the school just now. 剛才你的朋友在學校里找你。

　　② Children are often in hospital when they are young. 孩子們小的時候經常生病住院。

　?、?She is a good doctor in the hospital .她是醫院里的一名好大夫。

　　Ⅰ. at school表示“在學校、在上學”相對于在家里或在校外。如：

　?、?My son is at school now. He is not at home or somewhere else. 我兒子現在在學校，他不在家，也不在別的地方。

　?、?When my brother was at school, he studied very hard. 在學校時，我兄弟學習很用功。

　?、? in school “在求學、在上學”相對于有工作。如：

　　My daughter still in school She doesn’t work.。 我女兒還在上學，她不在工作。

　?。孩俸廷谟胊t school 強調所在場所或時間。③中的in school 則強調主語的身份是學生。因此，in school. 和 at school的著重點不一樣，通常不互換使用。

　?、? In a / the school “在學?！?，不一定指上學。類似的還有：

　　in hospital “生病住院”

　　in a / the hospital表“在醫院”(工作或探視病人等)

　　at table “在吃飯”

　　at a / the table “在桌邊”(有可能在聊天或看報)

　?、?Is your friend in school? 你的朋友在上學嗎?

　?、?Your friend looked for you in the school just now. 剛才你的朋友在學校里找你。

　?、?Children are often in hospital when they are young. 孩子們小的時候經常生病住院。

　?、?She is a good doctor in the hospital .她是醫院里的一名好大夫。