YOU SAID:
If I have a cat, I'll be happy.
INTO JAPANESE
猫があれば、私はさせていただきます。
BACK INTO ENGLISH
If you have a cat, I will be happy.
INTO JAPANESE
猫があれば、私は幸せになります。
BACK INTO ENGLISH
If you have a cat, I will be happy.
That didn't even make that much sense in English.