In this study we used a semantic battery assessing the conceptual, lexical, and metacognitive level in semantic relationships to predict expressive lexicon in preschool children with typical and atypical language development. Our regression analyses showed that the tests of our semantic battery altogether accounted for 24% of variance in expressive lexicon after controlling for age and phonological short-term memory. The ability to memorize picture-cue/word pairs that were linked by taxonomic relations made a unique contribution to the expressive lexicon, and was a reliable marker of delayed expressive vocabulary in a group of children with specific language impairment.