There are 3 Japanese scripts : Hiragana, Katakana & Kanji. Most of the Japanese sentences are written in Hiragana, Katakana & Kanji, all three.
Hiragana is used for the endings of verbs and for grammatical particles.
Katakana is used for transcription of words borrowed from foreign languages (except Chinese), like country names, personal names, etc.
Both Hiragana and Katakana letters are phonetic representations of sound, 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 'The department store is closed on Mondays' is written in :
Japanese Romaji : Depāto wa getsuyōbi ni yasumi desu. ;
Japanese traditional (Hiragana, Katakana and Kanji) : デパートは月曜日に休みです。; where Kanji = 月曜日 (getsuyōbi = Monday),休み (yasumi = holiday) ; Katakana = デパート(depāto = department store) and the rest is Hiragana.
Japanese Hiragana and Katakana (without Kanji) : デパートはげつようびにやすみです。 Note - The Kanjis in the sentence written in Japanese traditional, 月曜日 and 休み are replaced by their hiragana equivalents げつようび(getsuyōbi) andやすみ(yasumi) respectively.
Note : は(ha) is read (wa) only when it is used as the particle attached to the noun or the subject of a sentence. In other words, one writes は notわ for the particle wa. は(wa) is always used after the subject. In the example above, は(wa) comes after the subject depāto デパート (department store) .
Kanji is sometimes written in combination with Hiragana. In the above example yasumi (holiday) is written in Kanji as 休み and in Hiragana as やすみ. Note the み (mi) in Kanji.