YOU SAID:

He's my friend. So was i

INTO JAPANESE

彼は私の友人です。私もそうだった

BACK INTO ENGLISH

he is my friend I was too

INTO JAPANESE

彼は私の友達です 私もそうでした

BACK INTO ENGLISH

he's my friend so am i

INTO JAPANESE

彼は私の友達で、私もそうです

BACK INTO ENGLISH

he's my friend and so am i

INTO JAPANESE

彼は私の友達で、私もそうです

BACK INTO ENGLISH

he's my friend and so am i