YOU SAID:
Teacher can I use the bathroom? I don't know can you?
INTO JAPANESE
先生はトイレを使えますか?わかりませんか。
BACK INTO ENGLISH
Can the teacher use the toilet? Do you not understand?
INTO JAPANESE
先生はトイレを使うことができますか?分かりませんか?
BACK INTO ENGLISH
Can the teacher use the toilet? Do you not understand?
That didn't even make that much sense in English.