The vocabulary is limited, speech is slowed with a greater number of pauses, and the sentences are short and grammatically simplified, often repeated.
Research suggests that with the larger opening of the lips during CDS, infants are better able to grasp the message being conveyed due to the heightened visual cues.
[22] Some researchers[23] believe that CDS is an important part of the emotional bonding process between the parents and their child, and helps the infants learn the language.
[19] Children that learn the fastest are those who receive the most acknowledgement and encouragement of what they say, are given time and attention to speak and share, and who are questioned.
When fathers who are not depressed are able to provide the stimulation of CDS, infants respond well and are able to compensate from the deficit left by their mothers.
This finding is thought to be due to the amount of time parents spend with the child and the ways they interact; mothers from higher-status groups are found to say more to their children, use more variety, and speak in longer sentences.
[30] Shore and others believe that CDS contributes to mental development as it helps teach the child the basic function and structure of language.
[31] CDS may aid a child in the acquisition and/or comprehension of language-particular rules which are otherwise unpredictable;[31] an example is the reduction or avoidance of pronoun reversal errors.
In these instances, the outward style of the language may be that of baby talk, but is not considered actual "parentese", as it serves a different linguistic function (see: Pragmatics).
This can occur during bullying, when the aggressor uses baby talk to assert that the victim is weak, cowardly, overemotional, or otherwise inferior.
In this instance, the baby talk may be an expression of tender intimacy, and may perhaps form part of affectionate sexual roleplaying in which one partner speaks and behaves childishly, while the other acts motherly or fatherly, responding in "parentese".
Recordings show that 90% of pet-talk is spoken mostly in the present tense because people talk to dogs about what is happening now rather than the past or the future, which is twice as much as with humans.
A significant difference is that CDL contains many more sentences about specific bits of information, such as "This cup is red," because they are intended to teach children about language and the environment.
Pet-speech contains perhaps half the sentences of this form, as, rather than instructive, its primary purpose is as a social function for humans; whether the dog learns anything does not seem to be a major concern.
[38] Researchers Bryant and Barrett (2007)[39] have suggested (as have others before them, e.g., Fernald, 1992[40]) that CDL exists universally across all cultures and is a species-specific adaptation.
Other evidence suggests that baby talk is not a universal phenomenon: for example Schieffelin & Ochs (1983) describe the Kaluli tribe of Papua New Guinea who do not typically employ CDS.
Often, cultures lacking a form of CDS make up for it in other ways, such as involving the children more in everyday activities, though the reverse might also be a valid assessment.
[15] With respect to English-speaking parents, it is well-established[46] that Anglo-Saxon or Germanic words tend to predominate in informal speech registers, whereas Latinate vocabulary is usually reserved for more formal uses such as legal and scientific texts.
Syntactic patterns specific to this sub-vocabulary in present-day English include periphrastic constructions for tense, aspect, questioning and negation, and phrasal lexemes functioning as complex predicates, all of which occur also in CDS.
Baby talk, language regardless, usually consists of a muddle of words, including names for family members, names for animals, eating and meals, bodily functions and genitals, sleeping, pain, possibly including important objects such as diaper, blanket, pacifier, bottle, etc., and may be sprinkled with nonverbal utterances, such as goo goo ga ga.
In English, adding a terminal /i/ sound, usually written ⟨ie⟩, ⟨y⟩, or ⟨ey⟩, is a common way of forming diminutives often used as part of baby talk.