* the distinctive mode of speech used when speaking to infants and toddlers.
* Adults tend to speak with greater pitch variability, slower speech, shorter utterances, more word repetition and more question.
* They also enhance the clarity of vowels, adjust the sound of their voice, and exaggerate their facial expressions.
* Infants prefer this to adult-directed speech (ADS), even when it’s in another language.
* IDS is not universal, but it is common due to different cultures.