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 is a kind of word (part of speech) that tells about an action or a state. It is the main part of a sentence: every sentence has a verb. In English, verbs are the only kind of word that changes to show past or present tense. Every language in the world has verbs, but they are not always used in the same ways. They also can have different properties in different languages.