a caregiver (unconsciously) adapts their speech to aid a child in their language development. Key features: higher or melodic pitch, more frequent and longer pauses, slower and clearer speech, repetition, grammatically simpler sentences, more questions, use of hypophora, use of diminutives, use of nouns rather than pronouns, more frequent use of plural pronouns, expansion (develop a child's utterance), recasts (grammatically incorrect utterance repeated in correct form), politeness features, mitigated imperatives.