英语中什么是主语第三人称？

一般现在时语句中第三人称单数后面跟动词时，动词要加S,或es；

具体变化规则点这里：一般现在时第三人称单数后动词变化规则介绍

（For example）例如：

He teaches science sometimes;

She cooks dinner often;

It eats bones every day;

Tom plays basketball sometimes;

Lily reads story books occasionally;

My mother does housework every day;

Your father works every day;

Tom's sister rides a bicycle usually;

His brother always drives to the office ;

her uncle never eats grapes;

The dog loves to eat bones every day;

This cat often walks around on the street;

That elephant often bathes with its trunk;

一般现在时和现在进行时第三人称后的Be动词怎么用要牢记；

第三人称单数用 is ，

（For example）例如：

一般现在时-------

He is a teacher;

She is a doctor;

It is a dog;

Tom is a boy;

Lily is a girl;

现在进行时-------

He is working;

She is going;

It is eating;

Tom is reading book;

Lily is talking;

第三人称复数用 are ，

（For example）例如：

一般现在时-------

They are friends;

They are boys;

They are girls;

They are animals;

They are books;

现在进行时-------

They are working;

They are going;

They are eating;

They are reading book;

They are talking;

一般过去时和过去进行时第三人称后的Be动词怎么用要牢记；

第三人称单数用 was，

（For example）例如：

一般过去时-------

When he was young;

When she was a little girl;

When it was a puppy;

Tom was angry last night;

Lily was happy last night;

过去进行时-------

He was working;

She was going;

It was eating;

Tom was reading book;

Lily was talking;

第三人称复数用 were ，

（For example）例如：

一般过去时-------

They were very tired last night;

They were beautiful last night;

When They were young;

When They were baby animals;

When They were new books;

过去进行时-------

They were working;

They were going;

They were eating;

They were reading book;

They were talking;