YOU SAID:

I do not understand the point of his website.

INTO JAPANESE

彼のウェブサイトの要点がわかりません。

BACK INTO ENGLISH

I don't understand the point of his website.

INTO JAPANESE

彼のウェブサイトの意味がわかりません。

BACK INTO ENGLISH

I don't understand his website.

INTO JAPANESE

彼のウェブサイトがわかりません。

BACK INTO ENGLISH

I don't know his website.

INTO JAPANESE

彼のウェブサイトを知りません。

BACK INTO ENGLISH

I don't know his website.