YOU SAID:
There is one guy inside B
INTO JAPANESE
B の内部の一人の男があります。
BACK INTO ENGLISH
There is a man inside B.
INTO JAPANESE
Bの中に男がいる
BACK INTO ENGLISH
There is a man in B
INTO JAPANESE
Bに男がいる
BACK INTO ENGLISH
There is a man in B
You've done this before, haven't you.