YOU SAID:
I've been drinking watermelon.
INTO JAPANESE
私はスイカを飲んでいた。
BACK INTO ENGLISH
I was drinking watermelon.
INTO JAPANESE
スイカを飲んでいた。
BACK INTO ENGLISH
The watermelon was drinking.
INTO JAPANESE
スイカを飲んでいた。
BACK INTO ENGLISH
The watermelon was drinking.
You've done this before, haven't you.