Future Simple
Learn how to form the future simple, what it is used to describe, and how it differs from going to.
A simple look ahead
The future simple names a future action without extra detail.
The future simple describes a future action, decision, or prediction. It is formed with will, plus the base form of the verb, and this form stays exactly the same across every subject.
In She will work tomorrow., will work combines will with the base form work to describe a future action.
This lesson covers how the future simple is formed, what it describes, and how it compares to going to.
Before you begin
This is one of four topics on future tenses.
This lesson focuses on the future simple specifically. Future tenses as a whole includes three other topics, each covered in its own lesson.
If you would like an overview of future tenses in general, begin with the Future Tenses page.
The central idea
Will suits a decision made in the moment; going to suits a plan made earlier.
Compare a future simple sentence with a going to sentence describing a similar idea.
01
Future simple
The phone is ringing. I’ll get it.
02
Going to
I’m going to call her back later. I already decided.
The useful question is: was this decided just now, or earlier?
I’ll get it is a decision made at the exact moment of speaking. I’m going to call her back describes a decision already made before this moment.
Forming the future simple
Will, plus the base form, for every subject.
I will work. She will work. They will work.
Unlike the present simple, the verb form after will never changes, regardless of the subject. Will is also commonly shortened to ‘ll, as in I’ll or she’ll.
What the future simple describes
Three situations call for this tense.
A spontaneous decision
The phone is ringing. I’ll get it.
Decided at the exact moment of speaking, with no earlier plan.
A prediction
I think it will rain later.
Based on opinion or belief, rather than visible evidence.
A promise or offer
I’ll help you with that.
Will versus going to
Both describe the future, but from a different starting point.
will → a decision made now, or a prediction based on opinion: I’ll answer that. / I think she’ll win.
going to → a plan made earlier, or a prediction based on current evidence: I’m going to answer that email tonight. / Look at those clouds — it’s going to rain.
Avoiding will in time clauses
Words like when and before usually take the present simple instead.
I will call you when I arrive. (not when I will arrive)
After words like when, before, after, until and as soon as, the present simple is used to refer to the future, even though the whole sentence describes something that hasn’t happened yet.
A useful decision guide
Ask when this was decided, and whether a time clause is present.
01
Was this decided at this exact moment?
If so, will usually fits better than going to.
02
Is this a prediction based on opinion, rather than visible evidence?
Will often suits an opinion-based prediction.
03
Does the sentence include when, before, after, until, or as soon as?
If so, use the present simple after that word, not will.
04
Does the base form stay unchanged after will?
It should, regardless of the subject.
Common mistakes
Time clauses and the base form are the most frequent slips.
Will is not used after when in a future time clause.
Not: I will call you when I will arrive.
Correct: I will call you when I arrive.
The verb after will keeps its base form.
Not: She will works tomorrow.
Correct: She will work tomorrow.
An already-arranged plan is not usually described with will.
Not: I’ll meet Sam for lunch. I planned it last week.
Correct: I’m going to meet Sam for lunch. I planned it last week.
Check your understanding
Which sentence fits each situation?
Choose the correct answer for each pair.
The doorbell just rang. Which sentence fits this moment?
✅ Exactly! This decision is made at the exact moment of speaking.
❎ Not quite. Was this decision made in advance, or right now?
Was this planned earlier, or decided just now?
Which sentence is correctly formed?
✅ Exactly! The present simple follows “when” here, not “will”.
❎ Not quite. Time clauses beginning with “when” typically avoid “will”.
What tense usually follows “when” in a future time clause?
Which sentence is correctly formed?
✅ Exactly! The verb after “will” always keeps its base form.
❎ Not quite. Does the verb after “will” ever take an -s ending?
Compare this to how modal verbs are always followed.
Choose the best explanation
Select the sentence that explains the choice correctly.
Why does “I’m going to meet Sam for lunch. I planned it last week.” sound more natural than using “will”?
✅ Exactly! An already-arranged plan usually pairs more naturally with “going to”.
❎ Not quite. Focus on when this plan was actually decided.
Why is “I will call you when I will arrive.” not typically correct?
✅ Exactly! “When I arrive” is the standard pattern here.
❎ Not quite. Focus specifically on the second “will” in this sentence.
Quick review
Will names a future action without stating when it was decided.
The future simple is formed with will, plus the base form of the verb, unchanged across every subject.
It describes spontaneous decisions, predictions, and promises or offers.
Going to better suits a plan already decided before now, or a prediction based on visible evidence.
After when, before, after, until and as soon as, the present simple is used instead of will.
Remember
Check when the decision was made, and watch for time clauses.
Will suits something decided right now. If a plan was already made earlier, or the sentence includes a word like when or before, a different structure usually fits better.