YOU SAID:

there is a giant cat outside the window

INTO JAPANESE

窓の外には巨大な猫がいる

BACK INTO ENGLISH

There's a giant cat outside my window

INTO JAPANESE

窓の外に大きな猫がいる

BACK INTO ENGLISH

There is a big cat outside the window.

INTO JAPANESE

窓の外に大きな猫がいます。

BACK INTO ENGLISH

There is a big cat outside the window.