Craig: He's called Alfie.
Baby Alfie: [gurgles in Baby Language]
The Doctor: Yes, he likes that, "Alfie". Though personally, he prefers to be called "Stormageddon, Dark Lord of All".Often in fiction, babies who can't talk yet are treated as having their own esoteric language, similar to Animal Talk. Adults can't hope to understand this language without magic or phlebotinum, yet it's usually understood by all babies regardless of national origin. Usually, this will be the center of the plot for that particular story, although it may occasionally be used as a throwaway joke. Whether the babies have an intelligence to match their language varies greatly. In some works, it may just be a cutesy version of Hulk Speak. In others, the babies may in fact be geniuses, and unable to share their brilliance with the world — what a shame they forget it as soon as they begin to actually communicate. In others, the children seem to be relatively intelligent, but with poor decision skills and naivety, making them less capable. This last one is usually the most successful, but any of these forms can result in awkwardness if not handled well. Creepily, this might have an element of Truth in Television. Studies show that babies actually understand far more words than they’re actually able to speak because they’re so uncoordinated. It's called passive vocabulary. So for the first few years of life, it's very similar to communicating with the more intelligent pet animals. However, there is no universal "baby language" that babies can use to communicate with each other.
— Doctor Who, "Closing Time"
- One Baby Blues strip revealed that Hammie (at the time a toddler) could perfectly understand his younger sister Wren's baby talk, as well as speaking English. Zoe (a kindergartner) observed that she must have grown up too much as she couldn't make any sense of baby talk anymore.
- This was the premise behind Sheldon Mayer's classic comic series called Sugar and Spike, that all babies, no matter what species, spoke a universal "baby language".
- Sugar and Spike appeared in one issue of the Batman: The Brave and the Bold spin-off comic (which appears determined to not only have dafter plots than the series, but even more obscure guest stars). Batman gets turned into a baby, and can instantly understand them.
- GLX SPTZL GLAAH!
- Great things by Rose Of Pollux involves a little bit of this on the part of one of the Doctor's companions, whom he goes back to visit as an infant.
- In P.L. Travers' original Mary Poppins stories, babies could talk to each other, and also to animals and inanimate objects.
- In A Series of Unfortunate Events, toddler Sunny spoke in subtitled gibberish. Her speech was translated in the books.
- Apparently, in Diary of a Wimpy Kid, Manny knows several toddler slang terms. The only one we hear is "Ploopy," which Manny apparently considers quite offensive.
- Doctor Who: "A Good Man Goes To War" reveals that the Doctor can apparently speak baby. His companion doesn't buy it, and he calmly retorts "I speak everything". With the translation circuits, this may actually be true.
Craig: He's called Alfie.
- Proving that he can indeed speak baby is the episode "Closing Time", where the Doctor spends much of the episode translating a baby for his father, Craig.
Alfie: *babbling which can be heard in between the conversation*
The Doctor: Yes, he likes that; "Alfie". Though, personally, he prefers to be called "Stormageddon, Dark Lord Of All".
Craig: Sorry, what?!
The Doctor: That's what he calls himself.
Craig: How'd you know that?
The Doctor: I speak Baby.
The Doctor: No! He's your dad! You can't just call him "Not Mum"!
Craig: Not Mum?!
The Doctor: That's you. "Also Not Mum"; that's me. And everybody else is...
The Doctor: ..."Peasants". That's unfortunate.
- At the end of the episode that all changes. (Also, despite the Doctor's efforts to seem like he never appeared, Alfie's first actual spoken English word is Doctor.)
- Returns again in "The Girl Who Died", when the Twelfth Doctor translates a Viking baby's worries. Unlike the previous occasions, it's played for drama, not laughs.
- In Motherly Scootaloo, a My Little Pony: Friendship Is Magic Tumblr comic, apparently Lightning Blitz fits this, as the Ask Discord Hooves crossover shows (this makes sense, since it's the Doctor in pony form he's talking to).
- This is one of the hallmarks of Kurami; the titular infant's "speech" consists solely of "gek gek" and variations thereof.
- Rugrats is an interesting case in that three-year-olds like Angelica and Suzie can talk with the baby characters as well as with the adults. There's also Dil, who's three months old and can't be understood by the babies except for when he says occasional words like "Mine" or "Poopy".
- Kate from Arthur did this. However, she could also talk to Pal, the dog, implying that her Baby Language was on the same level as Animal Talk.
- Stewie on Family Guy may be an example, depending on how the writers feel that day. Stewie can speak perfectly, yet the family and most other adults are presumed to not being able to understand him (only Brian and most side characters can understand him). It gets lampshaded at one point where an angry Meg demands to know who was talking about her and everyone immediately blames Stewie, causing him to say "Oh, so now everyone understands me?" Word of God also says that everyone can understand Stewie, but choose to ignore him most of the time.
- Throughout the The Loud House episode, "Homespun", Lincoln and his sisters worry about their run-down house being destroyed by a tornado during a warning, so they all share their favorite memories of the house to learn to appreciate what they have. When it's one-year-old Lily's turn to share her favorite memory, Luan serves as her translator.
- In the PB&J Otter episode, "The Legend of Ponce de L'Otter", when the Otter kids need an idea on how to retrieve Ponce de L'Otter's lost telescope from the bottom of Lake Hoohaw, Baby Butter has an idea. However, because she can't really talk yet, her idea, which involves her using her diaper to absorb the water of the lake, is shown in an Imagine Spot. Unfortunately, because Peanut and Jelly are a few years older than her, they are unable to understand her.
- As mentioned above, babies do acquire a huge amount of passive vocabulary. Some psychologists recommend teaching babies to use sign language beginning at about nine months.
- It's also been proven that babies worldwide make roughly the same sounds until around six months, when they begin to copy the sounds of the language(s) used around them.
- Babies also have a tendency to use words in idiosyncratic ways (eg: "mama" for "all women or people wearing skirts") or even make up words of their own. Obviously, these personal languages are eventually phased out and/or normalized over time.