YOU SAID:
I don't understand the concept of this website.
INTO JAPANESE
私はこのサイトのコンセプトを理解していません。
BACK INTO ENGLISH
I do not understand the concept of this site.
INTO JAPANESE
私はこのサイトのコンセプトを理解していません。
BACK INTO ENGLISH
I do not understand the concept of this site.
You've done this before, haven't you.