YOU SAID:

Grandma said this is dumb

INTO JAPANESE

おばあちゃんはこれがダムだと言った

BACK INTO ENGLISH

Grandma told me that this is a dam

INTO JAPANESE

おばあちゃんがダムだと私に言った

BACK INTO ENGLISH

I told myself that grandma is a dam

INTO JAPANESE

私はおばあちゃんがダムだと自分に言った

BACK INTO ENGLISH

I told myself that grandma was a dam

INTO JAPANESE

私はおばあちゃんがダムだったと自分に言った

BACK INTO ENGLISH

I told myself that grandma was a dam