There are 3 Japanese scripts : Hiragana, Katakana & Kanji. Mostof the Japanese sentences are written in Hiragana, Katakana & Kanji, all three.
Hiragana is used for the endings of verbs and for grammatical particles.
Katakanais used for transcription of words borrowed from foreign languages(except Chinese), mostly English in origin, like country names, personal names, etc.
Both Hiragana and Katakana are syllabaries in which each symbol represents a spoken syllable, representing exactly the same set of sounds.
Kanji, which is a set of Chinese characters called sinograms, is used for the nouns and the radicals of verbs.
The Hiragana script has a Kanji equivalent (excepts the endings of verbs and the particles).
The Katakana script does not have a Kanji equivalent.
Whereas Hiragana and Katakana are phonetic representations of sound, Kanji conveys sounds as well as meanings.
A sentence in Japanese can be written in Hiragana and Katakana only (without Kanji).
Romaji (Roman letters) is simply the transliteration of Japanese in the Latin script. It is sometimes used for the convenience of foreigners, mostly on sign-boards and at stations.
The Romaji vowelsā,ī, ū,ē signify emphasis, and hence are also written asaa, ii, uuetee. ex.īe = iie
The vowel ō becomes ou and notooex. gakkō = gakkou
In Katakana, the emphasis on the vowel signifies a long sound written as ー. ex.nōto (notebook), will be written in katakana as : ノート
Example. The sentence 'Lisa speaks very good Spanish.' is written in :
Japanese Romaji : Lisa san wa supeingo ga jōzu desu.
Japanese traditional (Hiragana, Katakana and Kanji) : リサさんはスペインゴが上手です。; where 上手 (jōzu = very good) ; Katakana = リサ (Lisa), スペインゴ (supeingo = spanish) and the rest is Hiragana.
Japanese Hiragana and Katakana (without Kanji) : リサさんはスペインゴがじょうずです。 Note - The Kanji in the sentence written in Japanese traditional, 上手 is replaced by the Hiragana equivalent).じょうず(jōzu).
Note : The Katakana vocabulary consists of words which are only to be written in Katakana, with the exception of some Hiragana words written in Katakana for the sake of foreigners. ex. Milk (gyūnyū) is a Hiragana word , also written in Katakana Romaji (miruku) in restaurant menus and supermarkets.
To denote a language, 'go', essentially a Hiragana / Kanji word (ご / 語) is suffixed to the name of the country. Go means language in Japanese. ex. French = Furansu + go = Furansugo ( フランスご / フランス語)
Most languages are written in Katakana with the exception of Japanese, Chinese and Korean which are written in Hiragana / Kanji. Japanese - Nihongo (にほんご / 日本語) Chinese - Chūgokugo (ちゅうごくご / 中国語) Korean - Kankokugo (かんこくご / 韓国語)