it的复数形式是：they或者是them。因为it可能是人称代词主格；也可能是人称代词宾格。
拓展资料
it
1、（指提到过的或正在谈论的动物或事物）它
used to refer to an animal or a thing that has already been mentioned or that is being talked about now
‘Where's your car?’ ‘It's in the garage.’
“你的汽车在哪儿？”“在车库里。”
Did you see it?
你看见它了吗？
Start a new file and put this letter in it.
建立一个新档案，把这封信放进去。
Look! It's going up that tree.
瞧！它正在往那棵树上爬呢。
We have $500. Will it be enough for a deposit?
我们有500元。够不够作押金？
2、（指婴儿，尤指性别不详者）
used to refer to a baby, especially one whose sex is not known
Her baby's due next month. She hopes it will be a boy.
她的孩子该下个月出生。她希望会是个男孩。
3、（指已知或正在发生的事实或情况）
used to refer to a fact or situation that is already known or happening
When the factory closes, it will mean 500 people losing their jobs.
工厂如果关闭，就意味着500人要失业。
Yes, I was at home on Sunday. What about it? (= Why do you ask?)
是的，我星期天待在家里。怎么了？
Stop it, you're hurting me!
住手，你把我弄疼了！
4、（用以明确身份）
used to identify a person
It's your mother on the phone.
是你母亲来的电话。
Hello, Peter, it's Mike here.
喂，彼得，我是迈克。
Hi, it's me!
嗨，是我！
Was it you who put these books on my desk?
是你把这些书放在我桌子上的吗？
5、（用作形式主语或形式宾语，而真正的主语或宾语在句末）
used in the position of the subject or object of a verb when the real subject or object is at the end of the sentence
Does it matter what colour it is?
它是什么颜色重要吗？
It's impossible to get there in time.
不可能及时到达那里。
It's no use shouting.
喊也没有用。
She finds it boring at home.
她觉得待在家里无聊。
It appears that the two leaders are holding secret talks.
看来两位领导人正在进行密谈。
I find it strange that she doesn't want to go.
她居然不想去，我觉得奇怪。
本回答被网友采纳