YOU SAID:

My mom drinks a lot of beer.

INTO JAPANESE

私の母はビールを飲みます。

BACK INTO ENGLISH

My mother drinks a beer.

INTO JAPANESE

私の母は、ビールを飲みます。

BACK INTO ENGLISH

My mother was drinking beer.

INTO JAPANESE

私の母はビールを飲んでいた。

BACK INTO ENGLISH

My mother was drinking beer.