week 2

modality
In linguistics, modality is what allows speakers to evaluate a proposition relative to a set of other propositions. In standard formal approaches to modality, an utterance expressing modality can always roughly be paraphrased to fit the following template:
(1) According to [a set of rules, wishes, believes,...] it is [necessary, possible] that [the main proposition] is the case.
The set of propositions which forms the basis of evaluation is called the modal base. The result of the evaluation is called the modal force. For example the utterance in (2) expresses that, according to what the speaker has observed, it is necessary to conclude that John has a rather high income:
(2) John must be earning a lot of money.
The modal base is here the knowledge of the speaker, the modal force is necessity. By contrast, (3) could be paraphrased as ‘Given his abilities, the strength of his teeth, etc., it is possible for John to open a beer bottle with his teeth’. Here, the modal base is defined by a subset of John's abilities, the modal force is possibility.
(3) John can open a beer bottle with his teeth.
A more elaborate account of formal semantic approaches to modality is given in section 1.
Cross-linguistically, modality can be expressed by a variety of means, such as auxiliary verbs as in the examples (2) and (3), verbal morphology (mood) or adverbs. An overview of the various modal expressions across languages is given below in section 2.
Typological approaches to modality usually favour a slightly wider definition of modality and also include meanings which do not fit the template in (1) exactly. Section 3 provides an overview over the range of meanings commonly associated with modality.