①in+月、年 the morning/afternoon/evening/a week 表示時(shí)間

　　②on+具體某一天(幾月幾日)/某個(gè)假期(…Day)

　　③at+具體某點(diǎn)時(shí)間、某個(gè)假期(…Festival)/the weekend

　　①in…street 表示方位

　　②on…road/left/right

　　③at the…crossing/stop/某個(gè)具體的地點(diǎn)

　　①in the tree(不是樹上長(zhǎng)出來的)

　　②on the tree(樹上原來自己長(zhǎng)出來的)

　　表示時(shí)間：

　　① ago(……以前) later(……以后)

　　② before (在……以前) after(在 ……以后)

　　be 動(dòng)詞和助動(dòng)詞

　　1. be 動(dòng)詞(am/is/are)

　　主語 be 動(dòng)詞(原形) be 動(dòng)詞(過去式)

　　I am was He/she/it is was

　　We/you/they are were

　　2.助動(dòng)詞(do/does/did)

　　Do+非第三人稱單數(shù) +動(dòng)詞原形…?

　　…do/don't

　　Does+第三人稱單數(shù)

　　…does/doesn't

　　Did+所有主格

　　…did/didn't

　　What do you/they/we…

　　+動(dòng)詞原形?

　　I/They/We+動(dòng)詞原形…。

　　What does he/she/it…

　　He/She/It +(動(dòng)詞+S)….

　　What did you/they/we/ he/she/it…

　　I/They/We/ He/She/It +動(dòng)詞過去式。