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.
The tense can be shown in the verb. For example, am, is, and are are always present tense, and was and were are always past tense. Or the tense can be shown by adding words to the verb. In English, the words that we add to the verb are helping verbs or auxiliaries, like be, have, shall, will, and so on.