WILL BE VS GOING TO

WILL VS BE GOING TO
To express prediction – either WILL or BE GOING TO is used:
1. According to the weather report, it will be cloudy tomorrow.
2. According to the weather report, it is going to be cloudy tomorrow.
3. Be careful! You’ll hurt yourself!
4. Watch out! You’re going to hurt yourself! When the speaker is making a prediction (a statement about something s/he thinks will be true or will occur in the future), either will or be going to is possible.

There is no difference in meaning between 1 and 2. Either 3 or 4.

To express a prior plan – only BE GOING TO is used:
5. A: why did you buy this paint?
B: I’m going to paint my bedroom tomorrow.






6. I talked to Bob yesterday. He is tired of taking the bus to work. He is going to buy a car. That’s what he told me. When the speaker is expressing a prior plan (something the speaker intends to do in the future because in the past s/he has made a plan or decision to do it), only be going to is used. *in 5: speaker B has made a prior plan. She decided to paint her bedroom last week. She intends to paint her bedroom tomorrow.

In 6 : the speaker know Bob’s intention to buy a car. Bob made the decision in the past and he intends to act on this decision in the future. Will is not appropriate in 5 and 6.

To express willingness – only WILL is used:
7. A: The phone is ringing.
B: I’ll get it.




8. A: I don’t understand this problem.
B: Ask your teacher about it. She’ll help you. In 7: speaker B is saying: “I am willing, I am happy to get the phone.” He is not making a prediction. He has made no prior plan to answer the phone and uses will to show his willingness.

In 8: speaker B feels sure about the teacher’s willingness to help.
Be going to is not appropriate in 7 and 8.
*COMPARE:
Situation 1: A: Are you busy this evening?
B: Yes. I am going to meet Jack at the library at seven. We’re going to study together.
In situation 1, only be going to is possible. The speaker has no prior plan, so he uses be going to.
Situation 2: A: Are you busy this evening?
B: Well, I really haven’t made any plans. I’ll eat/I’m going to eat dinner, of course. And then I’ll probably watch/I’m probably going to watch TV for a little while.
In situation 2, either will or be going to is possible. Speaker B has not planned his evening. He is “predicting” his evening (rather than stating any prior plans), so he may use either will or be going to.