YOU SAID:

I accidentally played chess with an old man and he taught me new tricks

INTO JAPANESE

私は偶然、老人とチェスをして、新しいトリックを教えてくれた

BACK INTO ENGLISH

I casually played chess with the old man and taught me a new trick

INTO JAPANESE

私は気楽に老人とチェスをして、新しいトリックを教えてくれた

BACK INTO ENGLISH

I casually played chess with the old man and taught me a new trick