Lexical CDS categories were explored amid 40 Hebrew-speaking parents of infants in early pre-verbal, late-preverbal, single-word and early grammar stages during spontaneous parent–infant interactions. Two hundred utterances from each sample were transcribed, coded for types and tokens, and assayed. Results showed a notable increase in content word types from early to late pre-verbal stages, notable decline at the single-word stage, and a growth at the early grammar stage. Apparently, parents alter their use of content words to accommodate their child's linguistic development, attesting to dynamic/reciprocal parent–child interactions. Additionally, results support that verb use is equal to or higher than noun use by parents at all developmental stages.