The evolution of the Japanese language in Japan as the influence of English has affected it's use in a slang-like manner. Although the japanese language had originally adopted words from english (ex. teburu, hanbaaga, okke), french (anime, pan), and german (arubaito) the newer generations began to use english words as a sort of slang changing the meaning entirely from the original english one. Memo wo shite iru no? Means to be emailing off a cellphone etc... the word memo has been adopted and changed. Most jpop songs now a days include a great amount of english as in the songs from Hirai Ken (hitomi wo tojite, my love forever) and Korean Singer Boa in Every heart. Many restaurants and stores are named after random english and non english words such as Gasuto (Although spelled Gusto, which should be pronounced as written, not Gasto) etc...
Japanengrish is a result of western influence on japanese youth.
02 de enero de 2006