Contrasting Future Forms: "Be Going To" VS "Will"

Can you tell the difference between the sentences on the left and those on the right?

The sky is dark. I think it's going to rain soon.	Don't worry. It will rain someday.
There are signs of recovery. He's going to get well soon.	There is no sign of recovery. But I'm sure he will recover.
Workers are preparing their equipment. They are going to repair the building.	If you overload it, the machine will break down.

There are several verb forms used to talk about the future. The most common ones include be going to structure, will, and the present continuous / present progressive.

These three structures often carry distinct meanings, which can sometimes be tricky to differentiate. As a result, choosing the correct form isn't always straightforward. In this post, we will focus on the difference between be going to and will by examining how they are used in contrast.

Be Going To + Verb 1	Will + Infinitive
A. Planned intentions To express a planned intention, or a plan with an intention. The plan is made before the moment of speaking and some preparations may have been made. Workers are preparing their equipment. They are going to repair the building. He has bought building materials. I think he's going to renovate his house. Note: When it is not known whether the intention has been planned or not, either be going to or will may be used.	B. Unplanned intentions To express an unplanned intention. The intention or decision to do something is made right at the moment of speaking, usually with no preparation. There's the doorbell. I'll open the door. Have you heard from her? ~ No, not yet. I'll call her now. Note: Using will infinitive is the best way to express a strong determination. Okay. I will help you. (with stress on "will") We will make it!
C. 3rd and 2nd person's intentions To express or ask about an intention made by the second person (you), or the third (he, she, it, they). The negative form shows that there is no intention. Are you going to renovate the room? He isn't going to stay here.	D. 1st person's intentions Will is almost always used to express first person's intentions. However, the negative form may be used for all persons, and usually means "to refuse to do something". I will leave now! He won't stay here. (He refuses to stay.)
E. Near future To indicate near future events / actions. The sky is dark. I think it's going to rain soon. Where's today's paper? I'm going to read it.	F. Near and Remote future To indicate near or remote future events / actions. The local government will build more schools in rural areas. It's a nice place. We will enjoy staying here.
G. Assumptions with Signs To express assumptions when there is a sign or symptom that something is certainly going to happen in the near or remote future. The sky is dark. I think it's going to rain soon. There are signs of recovery. He's going to get well soon.	H. Mere Assumptions To express assumptions, expectations, belief, or doubt that something will happen in the future. Don't forget your coat. It'll probably be cold up there. (I expect it will be cold.) Onions will be expensive when harvests fail.

Exercise

Put the verbs into future "be going to" or "will infinitive".

1. Why are you moving the sofa? ~ I (repaint) this room.
2. The printer doesn't work again. ~ Really? I (call) the technician. I hope he's not busy.
3. How do we get to the museum from here? ~ I don't know, but I (ask) the policeman over there.
4. You (lend) me your dictionary, please? I need it. ~ Yes, certainly. Here it is.
5. You (buy) a new computer? ~ No, this one is still good.
6. My car is being repaired. You (give) me a lift?
7. Where's the flashlight? ~ It's in the drawer. What you (do) with it? ~ I (search) the warehouse. It's dark in there.
8. What a beautiful painting. Where you (put) it?
9. This curtain is very dirty. ~ Very well. I (have) it washed.
10. You (play) games all night? You are going to school tomorrow.