文档介绍：一、时态讲解:如今完成时
（1）构成：如今完成时由助动词have + 过去分词构成,助动词have 有人称和数的变化。第三人称单数用has，其余用have。
如今完成时的否认式直接在助动词后面加上not、疑问式是把助动词提到主语之前。以he old man has died for 4 months. ×
They have left only for 5 minutes. ×
以上三句话可以改为：
He has been here for 2 weeks。
The old man has ______ _______ for 4 months。
They have _____ _____ only for 5 minutes
2）have （has) been 和have (has) gone的区别：表示“曾到过某地”要用 “have （has） been”； 表示“已经去某地”要用 “have （has） gone”。试比较：（精品文档请下载）
Where has he been？ 他刚刚到哪里去了？(已经回来了）
Where has he gone？ 他上哪儿去了?（人不在)
They have been to Canada. 他们到过加拿大。（如今已经不在加拿大)
They have gone to Canada。 他们到加拿大去了。（可能在路上和已经到加拿大）。
3）如今完成时不能和表示过去的时间状语连用，如yesterday, last year, in 1976， two days ago, just now, when I came in，但可以和already， yet, sometimes， always, often, before， lately, recently, once， twice, ever， never等连用。例如：（精品文档请下载）
She has already come. 她已经来了。
I haven’t read it yet. 我还没读过这个。
I have met him before。 我从前曾见过他。
Ma Hong has always been a good student. 马红一直是个好学生.
（精品文档请下载）
I have often seen him in the street。 我经常在街上看见他。
They have never been to Yan’an。 他们从未去过延安。
I haven’t seen him lately。 我近来没看到他。
Irregular Verbs
Base Form
Past Form
Past Participle
bear
bore
born
beat
beat
beaten
become
became
become
blow
blew
blown
bring
brought
brought
build
built
built
buy
bought
bought
catch
caught
caught
choose
chose
chosen
come
came
come
do
did
done
drink
drank
drunk
drive
drove
driven
eat
ate
eaten
fall
fell
fallen
find
found
found
fly
flew
flown
get
got
got
give
gave
given
go
went
gone
grow
grew
grown
have
had
had
hear
heard
heard
keep
kept
kept
leave
left
left
lose
lost
lost
make
made
made
put
put
put
read
read
read
run
ran
run
say
said
said
see
saw
seen
sell
sold
sold
send
sent
sent
sing
sang
sung
sink
sank/sunk
sunk
take
took
taken
teach
taught
taught
write
wrote
wrote
am， is
was
been
are
were
be