Teaching assistant resumes are some of the easiest to write badly. Most TA work is real and substantive — running discussion sections, grading hundreds of papers, holding office hours, writing rubrics — but it tends to come out on the resume as "assisted the professor" or "graded assignments." Both true. Both invisible to anyone reading the resume against another candidate.
The TA postings that students compete for — paid TAs, graduate TAs, prestigious-course TAs, residential college tutors — are screened by faculty and department coordinators who know what the work actually entails. A bullet that says "led 3 weekly discussion sections of 18 students each, graded 270+ problem sets across the semester, and revised the section worksheet that the course adopted as the standard the following year" reads as someone who taught. A bullet that says "assisted with the course" reads as someone who attended. This page shows how to make that translation honest, plus a free tool that adapts your resume to any specific TA posting in two minutes.