How do you say
you yuki for me with my studies
in japanese

"私の研究を助けてくれた由紀に感謝します"and/or
"Watashi no kenkyū o tasukete kureta Yuki ni kansha shimasu"

You would say it as watashi no kenkyū o tasuketa Yuki, arigatō. Remember a very important factor with Japanese is that it is Noun verb subject, not subject verb noun. I hope this helped ^^

Correct porqsuenabien