will/shall do vs is/am/are going to do— B2 Grammar Exercises

The phone rings. You reach for it and say I'll get it. Later, your flatmate asks about dinner and you reply I'm going to make pasta; I bought the ingredients this morning. Same speaker, same evening, two different futures. The first was decided in the moment. The second was planned hours ago. That difference (when the decision was made) is the heart of this distinction.

English doesn't have a single future tense. It has several future forms, and choosing between them depends on what kind of future you mean. Will, shall, and going to are the three you need most often, and they're not interchangeable. Each one carries a specific signal about how the future is being framed.

The core distinction

The two main forms split along a simple line: going to for what was already planned or is already visible, will for what's decided now or predicted without evidence.

Form	Used for	Example
going to	Prior plans, intentions, predictions with visible evidence	We're going to repaint the kitchen next weekend.
will	Spontaneous decisions, offers, promises, predictions based on opinion	That bag looks heavy, so I'll carry it for you.
shall	Offers and suggestions with I/we (formal in statements)	Shall I open the window?

Form

Form	Positive	Negative	Question
going to	She is going to call.	She isn't going to call.	Is she going to call?
will	She will call.	She won't call.	Will she call?

In speech, will almost always contracts to 'll after pronouns: I'll, you'll, he'll, we'll. The full form will is used for emphasis or in formal writing. Going to is often pronounced gonna in fast speech, but is never written that way in formal contexts.

When to use going to

Plans and intentions decided before now

If you'd already decided before the moment of speaking, use going to. The plan exists in your head before the conversation starts.

• I'm going to start a Spanish course in September.
• They're going to move to Lisbon next year.
• We're going to look at the new flat on Saturday.

Predictions based on visible evidence

If you can see, hear, or otherwise sense the evidence right now, use going to. The clue is present; the result is future.

• Those clouds are black. It's going to rain.
• Watch out, you're going to drop that glass!
• She hasn't studied at all. She's going to fail the exam.

When to use will

Decisions made at the moment of speaking

If you decide as you speak, use will. The decision didn't exist a second ago.

• It's cold in here. I'll close the window.
• Actually, I'll have the salad instead of the soup.
• "The printer's jammed." "Don't worry, I'll fix it."

Offers, promises, and refusals

Will carries the speaker's commitment. Offers, promises, and emphatic refusals all use will (or won't).

• I'll help you with the boxes. (offer)
• I'll call you the moment I land. (promise)
• She won't apologise; she insists she was right. (refusal)

Predictions based on opinion, belief, or knowledge

When the prediction comes from what you think or know rather than what you can see, use will. Common with verbs like think, believe, expect, and after probably, definitely, maybe.

• I think Brazil will win the cup this year.
• She'll probably be late; she always is.
• The new model won't be cheap.

Predictions and certainties not based on a human plan

For things that don't depend on anyone's intention or visible evidence (ages, calendar facts, long-range certainties), will is the natural choice.

• She'll be thirty in April.
• The eclipse will be visible from northern Spain.
• Winter will arrive late this year, according to the forecasts.

When to use shall

Shall is alive in modern English but narrower than it used to be. Two uses remain common; the rest sound dated or legal.

Offers and suggestions with I and we

This is the everyday use of shall, especially in British English. The speaker offers help or proposes an action and asks for the listener's response.

• Shall I carry that for you?
• Shall we leave at seven?
• It's getting late; shall I call a taxi?

Formal statements with I and we

In formal writing and ceremonial speech, shall can replace will with first-person subjects. In everyday conversation, this sounds old-fashioned, so use will.

• We shall overcome. formal / rhetorical
• I shall return next month. formal
• I'll return next month. everyday

Two more future forms to keep in mind

Will, going to, and shall aren't the whole future system. Two other common forms cover situations these three handle awkwardly.

Present continuous: fixed arrangements with other people

Use the present continuous when the time and place are set and someone else is involved. The arrangement is already in the diary.

• I'm meeting Anna at six.
• They're flying to Berlin on Friday.

This overlaps with going to but is more specific — use going to when the intention is clear but the details might still shift.

Present simple: timetabled events

For events governed by a public timetable — transport, cinema, lessons, opening hours — use the present simple. The event isn't your plan; it's on a schedule.

• The train leaves at 9:15.
• The film starts at half past eight.

Future continuous: actions in progress at a future time

For an action that will be happening at a specific moment in the future, use the future continuous (will be + -ing): This time tomorrow, I'll be flying to Tokyo.

Signal words

Certain words and phrases tend to cluster around each form. They aren't strict rules, but they're strong signals.

Signal	Form	Example
I think / I believe / I expect	will (opinion)	I think it will work.
probably / definitely / maybe	will (opinion)	She'll probably forget.
look / listen / watch out	going to (evidence)	Look — it's going to snow.
clearly / obviously / by the look of it	going to (evidence)	By the look of it, they're going to cancel the match.
plan / intend / decide (to)	going to (prior plan)	We're going to redecorate.

Common mistakes

Will vs. going to: same situation, different reading

Sometimes both forms are grammatically possible, but they create different impressions. Compare:

Sentence	Reading
I'll get a new phone.	I've just decided — perhaps in response to something you said.
I'm going to get a new phone.	I've been planning to — possibly for weeks.
She'll be fine.	Reassurance based on belief or general optimism.
She's going to be fine.	Reassurance based on visible evidence (she's smiling, breathing, recovering).
I'll see you later.	General goodbye — no specific arrangement.
I'm going to see you later.	There's already an arrangement to meet.
We'll talk about it tomorrow.	Decided right now — a way of closing the current conversation.
We're going to talk about it tomorrow.	The meeting is already scheduled.

Quick summary

Related topics

• Present continuous for future arrangements
• Future simple: will
• Future continuous