YOU SAID:
i just had a cup of coffee
INTO JAPANESE
私はコーヒーを飲みました
BACK INTO ENGLISH
I had coffee
INTO JAPANESE
コーヒーを飲んだ
BACK INTO ENGLISH
Drank coffee
INTO JAPANESE
コーヒーを飲みました。
BACK INTO ENGLISH
I drank coffee.
INTO JAPANESE
コーヒーを飲みました。
BACK INTO ENGLISH
I drank coffee.
That didn't even make that much sense in English.