The phonology of the Persian language varies between regional dialects, standard varieties, and even from older varieties of Persian. Persian is a pluricentric language and countries that have Persian as an official language have separate standard varieties, namely: Standard Dari (Afghanistan), Standard Iranian Persian (Iran) and Standard Tajik (Tajikistan).[1] The most significant differences between standard varieties of Persian are their vowel systems. Standard varieties of Persian have anywhere from 6 to 8 vowel distinctions, and similar vowels may be pronounced differently between standards. However, there are not many notable differences when comparing consonants, as all standard varieties have a similar number of consonant sounds. Though, colloquial varieties generally have more differences than their standard counterparts. Most dialects feature contrastive stress and syllable-final consonant clusters. Linguists tend to focus on Iranian Persian, so this article may contain less adequate information regarding other varieties.