YOU SAID:

the dog sits on the bed

INTO JAPANESE

犬がベッドの上に座っています。

BACK INTO ENGLISH

The dog sits on the bed.

INTO JAPANESE

犬はベッドの上に座っています。

BACK INTO ENGLISH

She sits on the bed.

INTO JAPANESE

彼女はベッドの上に座っています。

BACK INTO ENGLISH

She sits on the bed.