Shin and Mill (2021) propose four steps children go through when learning "variable form use." Although I applaud Shin and Miller's focus on morphosyntactic variation, their accrual of evidence is post hoc and selective. Fortunately, Shin and Miller recognize this and encourage tests of their ideas. In support of their work, I share data…

While previous sociolinguistic research has demonstrated that children faithfully acquire probabilistic input constrained by sociolinguistic and linguistic factors (e.g., gender and socioeconomic status), research suggests children regularize inconsistent input-probabilistic input that is not sociolinguistically constrained (e.g., Hudson Kam &…