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 .44 to .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. (author abstract)