英语里面为什么动词后面都加S

题目

英语里面为什么动词后面都加S
He wants to catch a hare.
He wants to catch a hare.
The bear,the bear ,
The big,big polar bear.
He jumps in the water.
He swims across the lake.
He walks through the snow and he runs up the hill.
When he comes to the top,
He comes to a stop.
He looks around,
And what’s not there?
The hare, the hare, the arctic hare.

答案

只有第三人称单数的现在时态才加s
第一人称,第二人称,第三人称复数不加s
例如
I want to buy a new cellphone.
You run so fast.
They go to school by bus together.
这些都不加s