Will vs Going to — Plans, Decisions & Promises

B1 — grammar, listening, reading, writing

Sofía: In December I'm going to travel to Cartagena. Tickets: bought. Hotel: booked. Spreadsheet: ready.

Ben: Sounds fun! You know what? I'll go with you! Decided. Just now.

Kenji: And that is exactly the difference. Sofía planned it — Ben just decided it this second.

Abuela Carmen: And I will always be here waiting... with soup. That's a promise.

Common mistake: “Look at those clouds — it will rain.” — Correct: “Look at those clouds — it's going to rain.”

Use 'going to' for plans you already made and predictions you can see coming; use 'will' for decisions made right now, opinions about the future, and promises.

will vs going to — who decides, and when?
Situation	Form	Example
Plan already made	going to	I'm going to travel in December (tickets bought)
Decision right now	will ('ll)	You know what? I'll go with you!
Prediction with evidence	going to	Look at those clouds — it's going to rain
Prediction from opinion	will (I think...)	I think Colombia will win
Promise / offer	will / won't	I'll help you. I won't tell anyone.
Negatives	won't · am/is/are not going to	We aren't going to cook tonight

I'm going to travel to Cartagena in December — I bought the tickets.
You know what? I'll go with you! Decided. Just now.
I think Colombia will win tomorrow.
Look at those clouds — it's going to rain.
I'll always remember this trip.
I won't tell anyone. I promise.
We aren't going to cook tonight; the fridge is empty.
It won't be easy, but we'll try.
Will you help me with this exercise?
What are you going to do in December?
Do you think it will rain tomorrow?
Will you come to the party? Yes, I will.
Are you going to study tonight? No, I'm not.
Will it rain? I think it will.

Practice

The phone is ringing! — Don't worry, I ___ answer it. (will, am going to, going to)
Look at those clouds. It ___ rain. (will, is going to, won't)
I bought the tickets. We ___ travel in December. (are going to, will, would)
I think our team ___ win tomorrow. (is going to, won't, will)
'Will' is used for decisions made at the moment of speaking.
'Going to' is only for predictions without evidence.
I promise I ___ (not / tell) anyone.
She ___ (be) going to study medicine — she has already chosen the university.
You know what? I ___ (help) you right now.
Unscramble: I, think, it, will, rain, tomorrow
Unscramble: are, you, going, to, tell, her
Find the mistake: Look at those clouds — it will rain.
Find the mistake: We will to travel in December.
Find the mistake: I don't will tell anyone.
I will study tonight. — Write the negative form.
They are going to move to Cali. — Write the yes/no question.
Will you come to my party? — Answer with a short answer (Yes).
It's going to rain. — Write the negative form.
She won't pass the exam. — Write the affirmative form.
Will you practice English tomorrow? (short answer)
Are you going to sleep early tonight? (short answer, No)

Listening

Sofía: OK, December trip. I'm going to book the boat tour tomorrow.

Ben: I'll carry all the bags! I'm strong and reliable.

Kenji: I think you'll drop the bags in the sea, Ben.

Ben: That happened one time!

Abuela Carmen: Children, I'll make the sancocho for the trip. And Ben — you aren't going to carry the pot.

Ben: ...Fair. That's fair.

Reading

Ben's New Year plan, written in his notebook: 'This year is going to be different. I'm going to learn salsa — I have already paid for ten classes. I'm going to save money for a new camera. And I'm not going to lose my phone again.' Under the plan, there is a phone number and a note in different ink: 'Kenji, if you find this notebook, I'll buy you dinner. I lost it on the bus. Again. Some things will never change.'

Ben is going to learn salsa.
He has already paid for the classes.
Ben is going to buy a new phone.
Kenji wrote the New Year plan.

Frequently Asked Questions

What is the difference between 'will' and 'be going to'?

Use 'will' for spontaneous decisions made at the moment of speaking ('Wait, I will help you with those bags!') and promises. Use 'be going to' for pre-planned decisions or intentions decided before speaking ('I am going to study medicine next year').

How do predictions differ with 'will' vs 'going to'?

Use 'going to' when there is clear physical evidence right now in front of you ('Look at those black clouds! It is going to rain'). Use 'will' for general beliefs, opinions, or intuition ('I think humanity will colonize Mars one day').