suffix
nth-year student; nth-year pupil
Suffix attached to a number or ordinal to indicate a student's year in school (e.g., 一年生 for first-year student).
彼は大学の二年生です。
He is a second-year university student.
一年生のとき、日本語を勉強し始めた。
I started studying Japanese when I was a first-year student.