These questions ask you to choose among several ways of referring to the future. The deciding clue is usually not how certain the event feels, but when a decision was made, what supports a prediction, or who fixed the time.
Read the situation before choosing the form
First decide whether the sentence describes a decision, a prediction, an arrangement or a timetable. For a decision, ask whether it existed before the speaker began talking. For a prediction, ask whether the sentence points to evidence that can be seen, heard or otherwise observed now. For a future event with a stated time, separate a person's confirmed arrangement from a published schedule.
| Clue in the situation | Form to use |
|---|---|
| A decision made now, an offer, a promise, or a prediction introduced as an opinion | Use will followed by the base verb. |
| An intention formed earlier, without a fixed diary appointment | Use am, is or are going to followed by the base verb. |
| Visible or audible evidence points to a future result | Use am, is or are going to followed by the base verb. |
| A confirmed personal arrangement with a set time or place | Use the present continuous. |
| An official programme, service schedule or timetable | Use the present simple. |
Apply the clues in that order. A future time expression such as tomorrow does not select a form by itself. The surrounding facts must show whether you are reacting now, carrying out an earlier intention, following a personal diary entry or referring to an impersonal schedule.
The traps
| Tempting shortcut | How to reject it |
|---|---|
| Using will because an earlier plan sounds firm or certain | Certainty is not the deciding clue. If the intention already existed and there is no fixed personal appointment, choose be going to. |
| Using be going to for help offered only after a new situation appears | That intention did not exist beforehand. A response decided at the moment of speaking takes will. |
| Using will for every prediction | Look for present evidence. If something observable now points to the result, use be going to; reserve will for the opinion-based branch. |
| Using the present continuous for a time printed in an official programme | A published timetable takes the present simple. Keep the present continuous for a person's confirmed arrangement. |
| Using be going to merely because a prediction concerns the future | Without present evidence or an earlier intention, a phrase such as I think signals an opinion-based prediction with will. |
| Using the present simple for an immediate offer or an evidence-based prediction | The present simple belongs to the timetable branch here. A spontaneous response needs will, while current evidence needs be going to. |
Try it
Complete the sentence with the correct form of the verb in brackets: We decided last week what to do with the spare room, but we have not set a date. We ___ (repaint) it.
Complete the sentence with the correct form of the verb in brackets: 'The printer has run out of paper.' 'I ___ (refill) it now,' Kai replies, making the decision at that moment.
Complete the sentence with the correct form of the verb in brackets: According to the harbour timetable, the first passenger ferry ___ (depart) at 05:45 tomorrow.