YOU SAID:

i didnt now the bull was on the train

INTO JAPANESE

私は今、雄牛が電車に乗っていませんでした

BACK INTO ENGLISH

I had no bulls on the train now

INTO JAPANESE

電車には雄牛がいませんでした

BACK INTO ENGLISH

There were no bulls on the train

INTO JAPANESE

電車には雄牛はいませんでした

BACK INTO ENGLISH

There were no bulls on the train