四年级英语自问自答的句子包括：

问句：

How old are you？

答句：I am 9 years old.

问句：

What is your name？

答句：My name is [Your Name].

问句：

What is your job？

答句：I am a student.

问句：

What time is it？

答句：It is 3 o'clock.

问句：

Where will you go？

答句：I will go to school.

问句：

Do you have dinner？

答句：Yes, I do. And you？

问句：

What is in your classroom？

答句：Six windows, four lights and boards.

问句：

What is in your desk？

答句：A pencil-case, a pen and a ruler.

问句：

Where is my chair？

答句：They are in the study.

问句：

What clothes have we got？

答句：We have got a blue T-shirt.

问句：

What has it got？

答句：It's got green shoes.

问句：

Where is the playground？

答句：It is on the first floor.

问句：

Is this the TV room？

答句：No, it isn't.

问句：

Is it a teacher's desk？

答句：Yes, it is.

问句：

Is that your classroom？

答句：Yes, it is.

问句：

Do you have a library？

答句：No, we don't.

问句：

Are those green beans？

答句：No, they aren't.

问句：

Can I have some ice cream？

答句：No, you can't.

这些句子涵盖了年龄、姓名、职业、时间、地点、日常活动、物品位置等多个方面，适合四年级学生进行自问自答的练习。