Counterfactual conditionalCounterfactual conditionals (also subjunctive or X-marked) are conditional sentences which discuss what would have been true under different circumstances, e.g. "If Peter believed in ghosts, he would be afraid to be here." Counterfactuals are contrasted with indicatives, which are generally restricted to discussing open possibilities. Counterfactuals are characterized grammatically by their use of fake tense morphology, which some languages use in combination with other kinds of morphology including aspect and mood.
Imperative moodThe imperative mood is a grammatical mood that forms a command or request. The imperative mood is used to demand or require that an action be performed. It is usually found only in the present tense, second person. They are sometimes called directives, as they include a feature that encodes directive force, and another feature that encodes modality of unrealized interpretation. An example of a verb used in the imperative mood is the English phrase "Go.
Dynamic semanticsDynamic semantics is a framework in logic and natural language semantics that treats the meaning of a sentence as its potential to update a context. In static semantics, knowing the meaning of a sentence amounts to knowing when it is true; in dynamic semantics, knowing the meaning of a sentence means knowing "the change it brings about in the information state of anyone who accepts the news conveyed by it." In dynamic semantics, sentences are mapped to functions called context change potentials, which take an input context and return an output context.
Tense–aspect–moodTense–aspect–mood (commonly abbreviated ) or tense–modality–aspect (abbreviated as ) is a group of that are important to understanding spoken or written content, and which are marked in different ways by different languages. TAM covers the expression of three major components of words which lead to or assist in the correct understanding of the speaker's meaning: Tense—the position of the state or action in time, that is, whether it is in the past, present or future.
Free choice inferenceFree choice is a phenomenon in natural language where a linguistic disjunction appears to receive a logical conjunctive interpretation when it interacts with a modal operator. For example, the following English sentences can be interpreted to mean that the addressee can watch a movie and that they can also play video games, depending on their preference: You can watch a movie or play video games. You can watch a movie or you can play video games.
VerbA verb () is a word (part of speech) that in syntax generally conveys an action (bring, read, walk, run, learn), an occurrence (happen, become), or a state of being (be, exist, stand). In the usual description of English, the basic form, with or without the particle to, is the infinitive. In many languages, verbs are inflected (modified in form) to encode tense, aspect, mood, and voice. A verb may also agree with the person, gender or number of some of its arguments, such as its subject, or object.
Grammatical particleIn grammar, the term particle (abbreviated ) has a traditional meaning, as a part of speech that cannot be inflected, and a modern meaning, as a function word (functor) associated with another word or phrase, in order to impart meaning. Although a particle may have an intrinsic meaning, and may fit into other grammatical categories, the fundamental idea of the particle is to add context to the sentence, expressing a mood or indicating a specific action. In English, for example, the phrase "oh well" has no purpose in speech other than to convey a mood.
