YOU SAID:

i have twelve childeren in my basement

INTO JAPANESE

私は地下室に12人の子供がいます

BACK INTO ENGLISH

I have 12 kids in the basement

INTO JAPANESE

地下に12人の子供がいます

BACK INTO ENGLISH

There are 12 children in the basement

INTO JAPANESE

地下には12人の子供がいます

BACK INTO ENGLISH

There are 12 children in the basement