ACT Conventions of Standard English Practice Test 2026 - Free ACT Practice Questions and Study Guide

The main idea tested is choosing the natural complement after a form of “to be” that describes a person’s relation to something. When someone has used a tool regularly, the idiomatic way to describe that state is “familiar with” the thing. The sentence pairs that with evidence in the second clause—“she has used it many times”—so saying she is familiar with the new software fits smoothly and clearly.

The other phrases don’t fit as well here. “In awe of” expresses admiration, which doesn’t match the practical experience implied by repeated use. “Have confidence in” would not align with the be-construction in this sentence. And while “adept at” could work in some contexts, “familiar with” is the most natural and direct choice for describing someone who knows the software well because she’s used it often.