The modern Japanese writing system is a combination of two character types: logographic kanji, which are adopted Chinese characters, and syllabic kana. Kana itself consists of a pair of syllabaries: hiragana, used for native or naturalised Japanese words and grammatical elements, and katakana, used for foreign words and names, loanwords, onomatopoeia, scientific names, and sometimes for emphasis. Almost all Japanese sentences contain a mixture of kanji and kana. Additionally, Romanization of Japanese is common for foreign loanwords and personal names. Because of this mixture of scripts, in addition to a large inventory of kanji characters, the Japanese writing system is often considered to be the most complicated in use anywhere in the world.