外研版八年级上

外研版八年级上第1页/共35页Objectives第2页/共35页To

summarise

andconsolidate

the

use

ofmodalverbs

—

must,

can,

could

(forprediction)To

learn

the

imperative

forsuggestions

and

instructions●I

don’t

know

when

they’ll

be

here.

They

could

arriveatanytime.我不知道他们多会来，他们可能随时会来。This

new

drug

could

be

an

important

step

in

the fight

against

cancer.这种新药可能是攻克癌症过程中迈出的重要一步。Read

the

sentences

andconversations

and

pay

attentionto

the

circled

parts.What

Tdheophotnhe

eis

ryingimng.

eIt

caounld

?be

Nick.第3页/共35页第4页/共35页Who

sent

thepresent?

Can

itbeyour

brother?It

can’t

be

mybrother.

Heisstill

in

France.It

must

be

yourbrother.

Isawhim

in

yourroom

just

now.第5页/共35页1w.Tohrdatscionulrdedb.e

harmful!Betty,

you

must

know!But

he

could

have

trouble

hearing

youor

speaking

to

you.You

could

drop

him

and

hurt

himeven

more.Observe

the

following

sentencescarefully

and

pay

attention

tothe第6页/共35页第7页/共35页意义否定式用法can表可能性，有惊异怀疑、不相信之意、can’t用于否定句及疑问句could表推测，可能couldn’t用于肯定句、否定句和疑问句注意：用于疑问句时，can比could表

示的“可能性”要大。第8页/共35页情态动词must/can/could

表示推测之前我们学过情态动词can和could

表“能够，可以”等意义的用法。另外，can和could

还可表示对现在或将来的推测，意为“会,可能”。He

couldbe

inpain.他可能很疼。That

could

beharmful!那可能有害！Can/Could

this

be

true?这有可能是真的吗?第9页/共35页情态动词must

表示有把握的猜测，意为“一定，准是”，通常只用于肯定句。如：Betty,

you

must

know!贝蒂，你肯定知道！第10页/共35页请仔细对比下列一组句子：Who

sent

the

present?

Can

it

be

yourbrother?是谁送来的礼物啊？会是你哥哥吗？（询问可能性）It

must

be

your

brother.

I

saw

him

in

yourroom

just

now.肯定是你哥哥，我刚才看见他在你的房间里。（语气强烈，表示非常肯定）It

can’t

be

my

brother.

He

is

still

inFrance.不可能是我哥哥，他还在法国呢。（表示不可能）第11页/共35页第12页/共35页1.

Hide

under

a

table.Stay

away

from

windowsand

heavy

furniture.Keep

Clear

offires.5.

Stay

aw6.

In

the

m7.

On

abeLeavWe

thheatbushiladlinl

gwseqduiockolry

n…ot

do

ifanKeepecaarltmh,q…uaBkee

bhraapvpe

eannsd?behelpful.Move

away

from

buildings,

…ay

from

bridges

and

trees.ountains,

be

careful

of

falling

rocks.ach,

run

away

from

the

sea

and

movequickly

to

higher

ground.第13页/共35页1.

Don’t

jump

out

of

highbuildings.2.

Don’t

stand

near

streetlights

or

under

power

lines.第14页/共35页Swtaoyrdaws

ainyfrreodm.

windows

and

heavyfurniture.

Do

not

stand

near

street

lights

or

under

powerlines.Make

sure

he’s

warm.

Cover

him

with

acoat.Find

out

what’s

wrong

with

him.Do

not

jump

out

ofhigh

buildings.

On

a

beach,

run

away

fromthe

sea

andmovequickly

to

higher

ground.Observe

the

following

sentencescarefully

and

pay

attention

tothe第15页/共35页1.and

heavy

furniture.2.(stand)

near

street

lights

orunder

power

lines.3.(make

sure)

he’swarm.4.5.(notMake

sureFindDo

not

jump

out

ofjump)

high

buildings.6.Onabeach,

run

away

from

(run)

thesea

and

move

(move)

quickly

tohigherground.Stay

awayfrom

(stay)

windowsDon’t

standCover

him

witghaocoat.oRut

e(faindd)

wyha?t’s

wrong

withhim.第16页/共35页祈使句祈使句表达说话人对对方的叮嘱、劝告、希望、禁止、建议、请求或命令等。*一般以动词原形开头，无时态和数的变化。*常见的祈使句如下：动词原形构成的祈使句let’s构成的祈使句无动词祈使句第17页/共35页1.

动词原形或Be单词构成的祈使句此类祈使句暗含的主语是you，但通常省略。否定句往往由do

not

(don’t)或never开头。Have

a

nice

day!祝你度过美好的一天！

Don’t

waste

your

time!别浪费时间了！

Never

belateagain!再也不要迟到了！第18页/共35页Come

this

way,please.请走这边。Please

be

quiet,

boys!男孩们，请安静！第19页/共35页祈使句的句首或句末有时加please，还可以加上称呼语，用逗号与句子主体隔开。2.

let’s构成的祈使句第20页/共35页这类祈使句往往用于提出建议。Let’s

spend

this

weekend

in

thecountryside.这周咱们到乡下度周末吧。

Let’s

take

a

taxi,shall

we?我们坐出租车好吗？let's/let

us否定形式：第21页/共35页1.let

us

前可加don't，也可以let

us

notDon't

let

us

go

with

her

tomorrow=Let

usnot

go

with

hertomorrow.2.Let's,必须在其后加notLet's

not

go

with

her

tomorrow.3.无动词祈使句第22页/共35页在请求、命令和口号中，常用无动词祈使句，它实际上是省略了动词，从而使语句更简洁有力。Just

a

minute,

please!请稍等！This

way,

please!请这边走！4.在公共场合的提示语中，否定句常用：

NO+名词或动名词结构NO

photos

!NOsmoking!第23页/共35页can和could可以表示对现在或将来的推测。第24页/共35页意义否定式用法can表可能性，有惊异怀疑、不相信、can’t用于否定句及疑问句could表推测，可能couldn’t用于肯定句、否定句和疑问句“must

be+表语”表示对现在情况的推测，常用于肯定句，意为“一定，准是”。常见的祈使句如下：动词原形构成的祈使句let’s构成的祈使句无动词祈使句第25页/共35页注:

word 文档点击此处链接QuizI.用could/can/must或他们的适当形式填空。—

Is

that

woman

your

head

teacher?No,

it

can’t

be

her.

Our

headteacher

is

in

her

office.—Whose

schoolbag

is

this?It

must

be

Jenny’s.

It

has

her

nameonit.Listen!

Someone

is

knocking

at

the

door.Who

could

it

be?第26页/共35页and

read

loudly

inclass.第27页/共35页II.按要求完成句子。You

must

be

careful

with

yourhandwriting.(改为祈使句)

Be

careful

with

yourhandwriting.Talk

and

read

loudly

inclass.(改为否定句)Don’t

talk3.

The

girl

singing

in

the

next

room

mustbe

Lucy.(改为否定句)The

girl

singing

in

the

next

room

can’t

be

Lucy.III.

根据提示，用祈使句型写出句子。请举起你的右手。不要在课堂上大声说话。Please

put

up

your

righthand.咱们一起上学去吧。请来两块面包。Don’t

talk

loudly

in

class.再不要这样做了。Let’s

go

to

schooltogether.第28页/共35页Never

do

that

again.Two

pieces

of

bread,

please.IV.根据语境选用could,

must或can't填空。There's

a

bag

on

the

desk.

Whose

could

itbe?Ithinkthebook

must

be

Mike'sbecause

his

name

is

on

it.—Is

that

yoursister?—It

can't

be

her.

She

went

toShenyang

this

morning.第29页/共35页V.根据括号内所给英文提示语将下列句子翻译成英语。第30页/共35页晚上不要独自外出。(don't)Don't

go

out

alone

at

night.在课堂上请听老师的。(listen

to) Listen

to

the

teacher

in

class, please./Please

listen

to

the teacher

in

class.禁止拍照！(no)Nophotos!咱