Unit 3 Troubles He plays computer games.He waters flowers.He played computer games.Did he play basketball?No,he didn’t play basketball.He watered flowers.Did he water trees?No, he didn’t water trees.What does Sun Fei usually do?What did Sun Fei do yesterday?He usually goes skating.He went skating.时间状语句子结构yesterdayyesterday morning last night (week, year…)two days ago, (three years ago…)in 1990, (in 1998…)主语 + be (was/were) 主语 + 动词过去式The simple past tense表示过去某一时间所发生的动作或存在的状态，一般与表示故去的时间连用。一般过去时的句子中谓语动词要用过去式，动词的过去式有以下几种变化形式。1. 一般的动词后面加 – ed. 如： look looked2. 以 -e 结尾的动词后面直接加 -d.3. 以辅音 +y 结尾的动词， 变 y 为 i, 再加 -ed.4. 以重读闭音节结尾，末尾只有一个辅音字母的动词，先双写这个 辅音字母，再加 -ed.5. 不规则动词的过去式形式不以加 -ed 构成，需要逐个记忆a. Past simple of regular verbs1.clean - brush -2. like - live -3. study - try -4. stop - plan -规则动词的过去式ed ed clean brushlike lived d stud tried iedstop planped neda. Past simple of irregular verbsbe - break - buy - can - come - cost - do - drive - fall -get - give - go – hear- was/were broke bought could came cost did drove fell got gave went heard不规则动词的过去式Backa. Past simple of irregular verbsknow- leave - pay - put - ring - run - say - see- speak -stand - steal - take – teach- knew left paid put rang ran said saw spoke stood stole took taught不规则动词的过去式BackHere are some common irregular verbs:be--- was/werebreak---brokebuy---boughtcan---couldcome---camecost---costdo---diddrive---drovefall---fellget---gotgive---gavego---wenthear---heardknow---knewleave---leftpay---paidput---putring---rungrun---ransay---saidsee---sawspeak---spokestand---stoodsteal---stoletake ---tookteach---taught...
