YOU SAID:

I know your dad left to get the milk

INTO JAPANESE

あなたのお父さんが牛乳を取りに行ったのは知っています

BACK INTO ENGLISH

I know your father went to get milk.

INTO JAPANESE

あなたのお父さんが牛乳を買いに行ったのは知っています。

BACK INTO ENGLISH

I know your father went to buy milk.

INTO JAPANESE

あなたのお父さんが牛乳を買いに行ったのは知っています。

BACK INTO ENGLISH

I know your father went to buy milk.