YOU SAID:

I have a phone that has a green phonecase on it

INTO JAPANESE

私は緑色のケースが付いた携帯電話を持っています

BACK INTO ENGLISH

i have a mobile phone with a green case

INTO JAPANESE

私は緑色のケースの携帯電話を持っています

BACK INTO ENGLISH

i have a phone with a green case

INTO JAPANESE

私は緑色のケースの携帯電話を持っています

BACK INTO ENGLISH

i have a phone with a green case