Sophomore – 10th

Junior – 11th

Senior – 12th

In the US, it is 9th grade freshmen, 10th grade sophomores, 11th grade juniors, and 12th grade seniors for high schools.

Universities use the same system, but it is not done by year, but by the amount of credits the student has completed. We also don’t say “grade” for university.

For Japanese High school, you could say 1st year freshmen, 2nd year could be either sophomores or juniors, 3rd year seniors.

Gambatte.

10th = Sophmore

11th = Junior

12th = Senior

year 11 grade 12 senior

year 12 grade 13 freshman

first year university sophomore

Sophomore 10

Junior 11

Senior 12

Freshman–9th grade

Sophomore–10th grade

Junior–11th grade

Senior–12th grade

Then it repeats this order for college.

hope that helps!