Present and future deduction in English B2
Use must, might, may, could and cannot to grade conclusions about current situations and future possibilities.
Recognise the main present and future deduction patterns in authentic contexts.
Choose a form that accurately expresses match modal strength to the available evidence instead of stating guesses as facts.
Avoid errors that change time, agency, emphasis or speaker commitment.
Use the structure appropriately in problem-solving, prediction, investigation and careful conversation.
What present and future deduction communicates
Use must, might, may, could and cannot to grade conclusions about current situations and future possibilities.
The central purpose is to match modal strength to the available evidence instead of stating guesses as facts. A successful choice therefore preserves the proposition while making the intended relationship, viewpoint or degree of commitment visible to the reader.
How the pattern is built
Use this working formula: must / may / might / could / cannot + base or be + -ing. The formula is a decision path: it identifies the trigger, the clause architecture and the element that carries tense or modality.
The model “The server must be processing a large request.” shows the complete pattern in context. Rebuild the sentence from meaning to form instead of translating each word independently.
| Choice | Structure | Example |
|---|---|---|
| Strong deduction | must + base / be + -ing | The server must be processing a large request. |
| Open possibility | may/might/could + base | The update might solve the problem. |
| Impossibility | cannot + base / be + -ing | That cannot be the final version; two sections are missing. |
Choose by meaning, not by surface similarity
Neighbouring structures may contain similar words but perform different jobs. Compare the three reference patterns and name the intended effect before completing the sentence.
A reliable answer explains both why the chosen form works and why a plausible alternative would change the meaning, time relation, information focus or level of certainty.
| Meaning | Best route |
|---|---|
| a conclusion strongly supported by present evidence | Strong deduction |
| a possible present or future explanation | Open possibility |
| a conclusion ruled out by evidence | Impossibility |
Register, discourse and editorial control
This grammar is especially useful in problem-solving, prediction, investigation and careful conversation. Its value comes from helping the reader process a relationship efficiently, not from making the sentence sound artificially complex.
After editing, check recoverability, natural word order and consistency with the surrounding paragraph. If the marked structure creates ambiguity, return to a fuller or more neutral clause.