Benign paroxysmal positional vertigo is caused by calcium debris in the semicircular canals (canalithiasis), usually the posterior canal. Medications generally are not recommended for the treatment of this condition.
In grammar, tense is a category that expresses time reference. Tenses are usually manifested by the use of specific forms of verbs, particularly in their conjugation patterns. Basic 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.
A verb, from the Latin verbum meaning word, is a word (part of speech) that in syntax 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. Verbs have tenses: present, to indicate that an action is being carried out; past, to indicate that an action has been done; future, to indicate that an action will be done.