YOU SAID:
I'm going to school, (hopefully) on my bike tomorrow.
INTO JAPANESE
明日自転車で学校に行きます。
BACK INTO ENGLISH
I'm going to school by bicycle tomorrow.
INTO JAPANESE
明日は自転車で学校に行きます。
BACK INTO ENGLISH
I'm going to school by bicycle tomorrow.
That didn't even make that much sense in English.