YOU SAID:
Sorry, could not understand the email addresses starting at "obama". OK
INTO JAPANESE
"obama"で始まるメールアドレスを理解できませんでした。 OK
BACK INTO ENGLISH
I could not understand the mail address starting with "obama". OK
INTO JAPANESE
"obama"で始まるメールアドレスが理解できませんでした。 OK
BACK INTO ENGLISH
I could not understand the mail address starting with "obama". OK
You've done this before, haven't you.