YOU SAID:

i went to the store to go get some milk on a monday morning

INTO JAPANESE

月曜日の朝に牛乳を買いに店に行きました

BACK INTO ENGLISH

I went to the store to buy milk on Monday morning

INTO JAPANESE

月曜日の朝、牛乳を買いに店に行きました

BACK INTO ENGLISH

I went to the store to buy milk on Monday morning