Modal vocabulary in ordinary language
Modal vocabulary is everywhere. 'Must', 'might', 'could', 'couldn't', 'has to', 'in every case', 'no matter what', and 'there is a way in which' are all modal cues. Some of them point toward necessity, some toward possibility, and many of them are ambiguous between different kinds of modality, such as physical, logical, or epistemic.
For this unit, the default reading is metaphysical: we are asking what could or could not have been the case, not what we know or do not know. When a sentence says 'she must be home by now', that is an epistemic reading about inference from evidence. When it says 'she could not have been taller than her own mother at age ten', that is a metaphysical claim about what was possible. We will come back to the difference, but the first move is simply to notice that such sentences have a modal dimension at all.
Legal and scientific language is rich with modal vocabulary that often goes unrecognized. A statute that says 'the defendant must have known the risk' is making an epistemic or deontic modal claim, not a metaphysical one. A physicist who says 'nothing can travel faster than light' is making a claim about physical necessity that is stronger than mere regularity. Learning to hear these modal words and to classify the kind of modality they invoke is the gateway skill for everything else in this unit.
Be alert to cases where modal vocabulary is used merely for emphasis rather than for genuine modal force. When someone says 'you simply must try this restaurant', there is no claim about necessity or possibility being made. The 'must' is rhetorical. A faithful translation of this sentence into modal logic would leave the box out entirely. Distinguishing genuine modal claims from rhetorical emphasis is part of the recognition skill this lesson is training.
- Scan a sentence for modal auxiliaries such as 'must', 'might', and 'could'.
- Ask whether the intended modality is metaphysical, physical, epistemic, or deontic.
- Do not translate a modal sentence as if the modal word were decoration.
- Filter out cases where the modal word is purely rhetorical emphasis.
Takeaway: Modal vocabulary is a feature of everyday language; the first skill is spotting it, classifying the kind of modality it invokes, and taking it as seriously as the proposition it modifies.