过去进行时怎样变形，和一般过去式的变形一样吗

不一样。过去进行时的结构是was/were+V－ing(现在分词)，而一般过去时是V-ed(动词的过去式)
过去进行时: 过去某个时刻正在做某事
I was reading a book at seven o'clock yesterday morning. （主语是单数用was+V－ing ）
They were playing football at 3 yesterday afternoon.(主语是复数用were+V－ing )
一般过去时：过去做某事
含有be动词的，主语是单数用was，主语是复数用were
I was a student.
We were classmates.
含有助动词的，只要把动词改为过去式
They worked here three years ago.

不太一样，进行时的基本形式其实就是be加动词的ing形式，变的是be。比如你说的过去时，如果主语是单数或第三人称就用was，复数或第一、二人称则用were，我这样解释OK吗？

buy send lend be go fly sit teach read understand think make get spend write ring come have pay sell bring leave sweep see take 过去式 过去分词

buy bought bought
send sent sent
lend lent lent
be （am , is 的过去式是 was are 的过去式是were. 过去分词都是been)
go went gone
fly flew flown
sit sat sat
teach tought tought
understand understood understood
think thought thought
make made made
get-got-gotten
spend-spent-spent
write-wrote-writen
ring-ring-rung
come-came-come
have-had-had
paid-paid-paid
sell-sold-sold
bring-brought-brought
leave-left-left
sweep-swept-swept
see-seeing-saw-seen
take-took-taken

动词过去式的规则变化：
(1) 直接加-ed，如：work—worked; play—played; rain—rained; wait--waited
(2) 以辅音字母加y结尾的动词， 变y为i， 再加-ed, 如:carry—carried; study—studied; try—tried;
(3) 以重读闭音节结尾的动词，如果末尾只有一个辅音字母， 应双写这一个辅音字母，再加-ed, 如: stop—stopped; plan--planned
(4) 以不发音字母-e结尾的动词，直接加-d, 如：use—used; change—changed; like—liked; live—lived; love—loved
( 5)不规则动词过去式的变化：

原 形 过去式 含 义 原 形 过 去 式 含 义
be,am,is
are
begin
break
bring
build
buy
can
catch
come
do
draw
drink
drive
eat
fall
feel
find
fly
get
give
go
grow
Have,has
hear
hold
hurt
keep
know
was
were
began
broke
brought
built
bought
could
caught
came
did
drew
drank
drove
ate
fell
felt
found
flew
got
gave
went
grew
had
heard
held
hurt
kept
knew
是
是
开始
打破
带来
建造
买
能
抓,赶上
来
做
画
喝
驾驶
吃
落下
感到
找到
飞
得到
给
去
生长
有
听见
握住
伤害
保持
知道 leave
let
learn
make
meet
put
read
ring
run
say
see
sell
sing
sit
speak
stand
swim
take
teach
tell
think
throw
Understand
wear
win
write
left
let
learnt,learned
made
met
put
read
rang
ran
said
saw
sold
sang
sat
spoke
stood
swam
took
taught
told
thought
threw
understood
wore
won
wrote
离开
让
学习
制造
遇见
放置
读
(铃)响;打电话
跑
说
看见
卖
唱
坐
发言
站
游泳
拿走
教
告诉
想;思考
扔
明白
穿
赢;获胜
写

动词加ing的变化规则
　　1．一般情况下，直接加ing，如：cook-cooking
　　2．以不发音的e结尾，去e加ing，如：make-making, taste-tasting
3．如果末尾是一个元音字母和一个辅音字母，双写末尾的辅音字母，再加ing，如：run-running, stop-stopping

. 第三人称单数的构成方法
与名词的单数变复数规则大致一样，即：
(1) 一般情况下由动词后加-s构成：work / works，read / reads等。
(2) 以s, x, z, sh, ch 以及字母o结构的动词，后加-es：guess / guesses, mix / mixes, go / goes, buzz / buzzes, finish / finishes, catch / catches等。
(3) 以辅音字母加y结尾的动词，应将y改为i 再加-es：fly / flies, study / studies等。
【注】① 有个别的变化不规则，如have / has, be / is等。

不一样.