YOU SAID:
晩餐はまだまだ終わらない
INTO JAPANESE
晩餐はまだディナーわらない
BACK INTO ENGLISH
Supper hasn't been dinner yet
INTO JAPANESE
夕食はまだ夕食になっていない
BACK INTO ENGLISH
Supper is not yet dinner
INTO JAPANESE
夕食はまだ夕食ではありません
BACK INTO ENGLISH
Supper is not yet supper
INTO JAPANESE
夕食はまだ夕食ではありません
BACK INTO ENGLISH
Supper is not yet supper
That didn't even make that much sense in English.