Correction #1: It was not the technology that he was interested in.
Correction #2: It was not the technology that interested him.

Wrong word choices can occur for many reasons. The student may not know the appropriate idiom or may confuse two similar words, such as uninterested and disinterested. Writing from A to Z has a list of commonly confused pairs on pages 502-504.

Check the following resources for useful practice material: 1) Guide to Grammar and Writing, 2) Colleen Hildebrand's UCI Correction Symbols with hyperlinks.