YOU SAID:

I swear that girl is always running her mouth on things she don't know nothing about.

INTO JAPANESE

あの娘は、自分が何も知らないことについていつも口を滑らせていると思う。

BACK INTO ENGLISH

I think that girl is always letting slip things she knows nothing about.

INTO JAPANESE

あの女の子はいつも自分が何も知らないことを口を滑らせているように思う。

BACK INTO ENGLISH

It seems like that girl is always letting slip things she knows nothing about.

INTO JAPANESE

あの女の子は、いつも自分が知らないことを口にしてしまうようだ。

BACK INTO ENGLISH

That girl always seems to say things she doesn't know.

INTO JAPANESE

あの女の子はいつも知らないことを言っているようだ。

BACK INTO ENGLISH

That girl always seems to be saying things she doesn't know.

INTO JAPANESE

あの女の子はいつも知らないことを言っているようだ。

BACK INTO ENGLISH

That girl always seems to be saying things she doesn't know.