1、定义：表示将要发生的动作或存在的状态，以及打算、计划或准备某事。句中一般含有表示将来的时间状语，如：tomorrow morning，next week，this afternoon等表示将来的时间状语。

2、构成：

① be gong to +动词原形

如：I am going to see a Beijing opera tomorrow.

We are going to meet at bus stop at half past ten.

Dad and I are going to see a Beijing opera this afternoon.

② will +动词原形

如：They will go swimming this afternoon.

3、be going to 和will 区别：

① be going to表示经过事先安排、打算或决定要做的事情，基本上一定会发生;will则表示有可能去做，但不一定发生，也常表示说话人的临时决定。

如：I am going to take part in a party this evening.

They are cleaning the library now. I’ll go and join them.

②be going to表示近期或眼下就要发生的事情;will表示的将来时间则较远一些。如：He is going to write a letter tomorrow. I will meet her one day.

③ be going to还可以用来表示有迹象表明某件事将要发生，常用于天气等自然现象。如：Look! It’s going to rain.

4、一般将来时句型转换：

肯定句 否定句 一般疑问句及回答

She is going to have a picnic tomorrow. She isn’t going to have a picnic tomorrow. —Is she going to have a picnic tomorrow?—Yes, she is. / No, she isn’t.

They will go swimming this afternoon. They will not(won’t) go swimming this afternoon. —Will they go swimming this afternoon?—Yes, they will. / No, they won’t.