Grammatical tenseIn grammar, tense is a that expresses time reference. Tenses are usually manifested by the use of specific forms of verbs, particularly in their conjugation patterns. The main tenses found in many languages include the past, present, and future. Some languages have only two distinct tenses, such as past and nonpast, or future and nonfuture. There are also tenseless languages, like most of the Chinese languages, though they can possess a future and nonfuture system typical of Sino-Tibetan languages.
Copula (linguistics)In linguistics, a copula (plural: copulas or copulae; abbreviated ) is a word or phrase that links the subject of a sentence to a subject complement, such as the word is in the sentence "The sky is blue" or the phrase was not being in the sentence "It was not being co-operative." The word copula derives from the Latin noun for a "link" or "tie" that connects two different things. A copula is often a verb or a verb-like word, though this is not universally the case. A verb that is a copula is sometimes called a copulative or copular verb.
Auxiliary verbAn auxiliary verb (abbreviated ) is a verb that adds functional or grammatical meaning to the clause in which it occurs, so as to express tense, aspect, modality, voice, emphasis, etc. Auxiliary verbs usually accompany an infinitive verb or a participle, which respectively provide the main semantic content of the clause. An example is the verb have in the sentence I have finished my lunch. Here, the auxiliary have helps to express the perfect aspect along with the participle, finished.
Future tenseIn grammar, a future tense (abbreviated ) is a verb form that generally marks the event described by the verb as not having happened yet, but expected to happen in the future. An example of a future tense form is the French aimera, meaning "will love", derived from the verb aimer ("love"). The "future" expressed by the future tense usually means the future relative to the moment of speaking, although in contexts where relative tense is used it may mean the future relative to some other point in time under consideration.
Grammatical aspectIn linguistics, aspect is a that expresses how an action, event, or state, as denoted by a verb, extends over time. Perfective aspect is used in referring to an event conceived as bounded and unitary, without reference to any flow of time during ("I helped him"). Imperfective aspect is used for situations conceived as existing continuously or repetitively as time flows ("I was helping him"; "I used to help people"). Further distinctions can be made, for example, to distinguish states and ongoing actions (continuous and progressive aspects) from repetitive actions (habitual aspect).
Modal verbA modal verb is a type of verb that contextually indicates a modality such as a likelihood, ability, permission, request, capacity, suggestion, order, obligation, necessity, possibility or advice. Modal verbs generally accompany the base (infinitive) form of another verb having semantic content. In English, the modal verbs commonly used are can, could, may, might, shall, should, will, would, ought to, used to and dare A modal auxiliary verb gives information about the function of the main verb that it governs.
Grammatical categoryIn linguistics, a grammatical category or grammatical feature is a property of items within the grammar of a language. Within each category there are two or more possible values (sometimes called grammemes), which are normally mutually exclusive.
Irrealis moodIn linguistics, irrealis moods (abbreviated ) are the main set of grammatical moods that indicate that a certain situation or action is not known to have happened at the moment the speaker is talking. This contrasts with the realis moods. Every language has grammatical ways of expressing unreality. Linguists tend to reserve the term "irrealis" for particular morphological markers or clause types. Many languages with irrealis mood make further subdivisions between kinds of irrealis moods.
Isolating languageAn isolating language is a type of language with a morpheme per word ratio close to one, and with no inflectional morphology whatsoever. In the extreme case, each word contains a single morpheme. Examples of widely spoken isolating languages are Yoruba in West Africa and Vietnamese (especially its colloquial register) in Southeast Asia. A closely related concept is that of an analytic language, which uses unbound morphemes or syntactical constructions to indicate grammatical relationships.
Perfective aspectThe perfective aspect (abbreviated ), sometimes called the aoristic aspect, is a grammatical aspect that describes an action viewed as a simple whole; i.e., a unit without interior composition. The perfective aspect is distinguished from the imperfective aspect, which presents an event as having internal structure (such as ongoing, continuous, or habitual actions). The term perfective should be distinguished from perfect (see below). The distinction between perfective and imperfective is more important in some languages than others.
