YOU SAID:

My father left me at the age of 3 to go get milk

INTO JAPANESE

父はミルクを取りに行くために3歳で私を置き去りにした

BACK INTO ENGLISH

My father left me at the age of three to go get some milk.

INTO JAPANESE

父はミルクを取りに行くために3歳の時に私を置き去りにしました。

BACK INTO ENGLISH

My father left me at the age of three to go get some milk.