Purpose: The present article reports on the implementation and results of a randomized intervention trial targeting the literate language skills of prekindergarten children without identified language disorders but with low oral language skills. Method: Children (N = 82; 45 boys and 37 girls) were screened-in and randomized to a business-as-usual control or to the pull-out treatment groups in which they received 4 instructional units addressing different sentence-level syntactic and semantic features: prepositions, conjunctions, adverbs, and negations. The intervention was delivered by paraprofessionals in small groups in the form of 20-min lessons 4 times a week for 12 weeks. Results: Overall, children receiving the supplemental instruction showed educationally meaningful gains in their oral language skills, relative to children in the control group. Significant group differences were found on researcher-designed oral language measures, with moderate to large effect sizes ranging from 0.44 to 0.88 on these measures. Conclusions: The intervention holds the potential to positively affect understanding and production of syntax and semantic features, such as prepositions and conjunctions, in young children with weak oral language skills.