YOU SAID:

I have a coworker who is named derek and he is wearing a blue shirt.

INTO JAPANESE

デレクという同僚がいて、彼は青いシャツを着ています。

BACK INTO ENGLISH

A colleague named Derek is wearing a blue shirt.

INTO JAPANESE

デレクという同僚が青いシャツを着ています。

BACK INTO ENGLISH

A colleague named Derek is wearing a blue shirt.