early language development in babies and toddlers

Early language development: the first 24 months

This blog post outlines language development up to the age of 2:

It covers babies’ first utterances up to their ability to stringfirst words together
I talk about how their vocabulary expands and how it is structured within their brain
I also cover their early speech development (and which speech errors naturally occur during this time)

The first 12 months

The first question all parents ask themselves as they sit in front of their babies, swinging rattles, squeezing squeaky giraffes, and massaging tummies: When do children produce their first words?! Just last night, my husband Frank told how difficult those first months were because he wasn’t quite sure how to communicate with our son.

That’s why I wanted to briefly summarise in today’s blog which phases children go through and what we can observe during these times. You can also check out our podcast Logopädie kompakt. In one episode we share our experiences as speech therapists and how we experienced this time with our children (it is in German though).

For the sake of simplicity, I refer to parents, mothers and fathers here in the blog, but of course I mean all caregivers/guardians of a child. All those who take care of the little bundles of joy and give them their time, love and patience. Those who laugh, cry, scream, squeal and romp around with them :-).

And please bear in mind when reading: the ages given here are a rough guide. Children all develop differently. Sometimes we have the feeling that the child learns overnight, and we think we are looking at a different child, sometimes we wait weeks for a progression. It is important not to get overly anxious and to observe carefully. If you are worried, don’t carry these worries around with you. Follow your gut feeling and ask questions if you are unsure. Talk to friends or other parents, talk to your paediatrician, or seek advice from non-medical professionals (e.g., speech and language therapists).

Squeaking and burping: The pre-linguistic phase of language development

The first months of language development are also described as the pre-linguistic phase because children’s utterances are not yet bound to meaning (cf. Yavas, 1998). When babies squeak or say “ba”, they are not yet trying to name a toy or ask grandma to give them the cuddly bear.

The first utterances we can observe are, for example, vegetative sounds, including smacking or burping, or reflexive reactions, such as sneezing.

Of course, crying is also one of the very first utterances. Parents learn very quickly that there are different forms of crying. Sometimes their belly is squeezing, sometimes they are complaining about the bright light in their face. A rough distinction can be made between the “normal cry” and the “cry of pain”. What is exciting here, as Mampe and his colleagues (2009) found out in their study, is that the speech melody of the normal cry depends on the mother tongue. So, the French child cries differently than the German child! This clearly shows how early babies learn to perceive their surrounding language and how this affects their utterances.

If you want to learn more about this, I recommend watching Patricia Kuhl’s TED Talk. It is in English, but with German subtitles and a German transcript.

Speech sound development

During the first months of language development, children learn to produce sounds voluntarily. They enjoy trying things out, playing with their tongues and lips, and they manage to produce vowels (a, e, i, o, u) from about 3-4 months. And what also happens, what the parents have been eagerly waiting for: the children start to laugh audibly. Yay!

At about 5-6 months, so-called babbling starts. A rough distinction is made between two babbling phases (if you want to know more and more detailed information, you can find it here: Fox-Boyer & Schäfer, 2015; Natani, Ertmer & Stark, 2006).

During the first babbling phase, they experiment with sounds, they change the volume and pitch, and we hear the first combinations of consonants and vowels (e.g. “ma” and “ba”). These productions are “universal”, i.e., all children can produce all the sounds of this world. In the second babbling phase (from about 9 months), the consonant-vowel utterances become longer (e.g. “gagaga”) and finally more versatile (e.g. “bagadidi”).

During this time, the utterances also adapt to the surrounding language, so there is lively babbling in Persian, Russian or Japanese. And that’s a good thing, because a review study by Morris (2010), who looked at various research studies on babbling, found that there is a connection between babbling and later language development. Two-year-old children who spoke little compared to their peers showed less babbling beforehand (see also Fasolo et al., 2008).

There it is, the first word!

Around the first year of life, all parents are eagerly awaiting the moment when their baby utters their first word. But these first words are not so easy to identify. Many of them sound exactly like babbling. One of my son’s first words was “babe”, a sound combination we had heard months before. So, what makes such a string of sounds a word? Well, Ragnar used to say the word when we sat on the bed and played the game “lamp on, lamp off”. That means he always associated the word “babe” with the lamp. And he systematically began to link this particular sound combination with the meaning “the thing that mummy always turns on and off”. Therefore, the important factor was not that the word had to sound or resemble adult language, but that the same utterance was consciously used for one particular object.

It’s amazing what the little rascals achieve in the first 12 months! But even as parents you can give yourself a big pat on the back. Because it is damn exhausting to follow the children’s attention, to give them linguistic input without much coming back. To provide them with a language role model again and again and to offer them space to communicate to make it easier for them to kick off their language development.

13-24 months

I remember well, the first 3-4 words were finally there, and I thought yay, now we can chat with each other and I can respond better to his needs. Unfortunately, after the first few words it took a long time until the next was acquired, and then until the next one appeared. So don’t be disappointed.  Each new word is hard work for the little ones.

The word factory begins its work

After all, children must do many tasks at the same time when learning words: they see people and objects in different contexts. They have to understand how these relate to each other and what different things mean. The questions “What does this thing look like?” and “What can I do with it?” play an important role here. For example, you can eat an apple, it is round…. You can also eat a banana, but it looks completely different. Both are in the kitchen in the fruit bowl. In addition, they hear a flood of language and must find out which of them is linked to the object “apple” or “banana”. And when they have heard and understood a term, they have to make a sound chain that sounds similar to what the other speaker said. Then they need to figure out “hmm, my aunt offered me that yellow crooked thing to eat. I know that! There’s a similar thing in our kitchen. What she said to me were many sounds. But I only remembered “Nane”, /n/ and /a/ I can already say. I know /n/ from “nose” and /a/ from “dad”. So I’ll try “nana” the next time she holds something like that in front of my nose”. And the aunt is delighted when she pulls a banana out of her bag the next time she visits and the nephew babbles “Nana”.

The lexicon grows and adapts

Word meaning and word form of “banana” have been linked by the child. The new word is stored in the lexicon. In building the lexicon, understanding precedes speaking. This means that children can already understand many more words than they can produce themselves. From about 10 months, children show an understanding of words (or receptive vocabulary), while the first spoken words (this is called expressive vocabulary) are not expected until about 12-13 months. When learning new words, children match the new sound chains with sounds and sound combinations that they have already stored (e.g., Graf Estes et al., 2016). This is why it is easier for them to learn new words that sound like familiar ones. They already have word templates for these, which they try to use again or slightly modify. My daughter Thorvi, for example, helped to prepare our potato salad the other day. Egg yolk and egg white were not yet stored in her lexicon. “egg white” was quickly grasped because she knew both the words “egg” and “white”, “egg yolk” became “egg yoyo” because she has played with her brother’s yoyo many times. Then, when I told her “egg yolk” several times via corrective feedback, she started to adapt her word template and finally called it “egg yolk”.

And so, over time, the children’s utterances continue to be updated, become clearer and approach the adult word form. Ragnar referred to himself as “Nana” at the beginning, then “Nager”, followed by “Rana” until he could finally say “Ragnar”. Words productions are also differ within a conversation. For example, while peeling potatoes, the potato is sometimes “Papoffel”, sometimes “Toffel” or “Tatel”. This variability in word production is completely normal up to about 3 years of age and is particularly evident with longer words or multi-word utterances (cf. Schäfer & Fox, 2006). I find these new word creations and word variations totally exciting.

When the lion becomes a goat – the lexicon is constantly updated

Grandma walks through the zoo with her granddaughter, watching the lions with wide eyes as they leisurely stroll from the rock to the feeding place to get their lunch. Then they are off to the petting zoo, where the goats eat their grass with relish. The little one happily points at the goat and says “lion”. Oops, what happened there? This is a classic example of overgeneralisation (or over-extension). The characteristics that the child has stored for the lion (has 4 legs, has a mouth to eat) are linked to the same word form (“lion”). So all animals that have 4 legs and a mouth to eat are called a “lion”. It is fantastic how the child has learned to recognise and match features in different objects. Over time children must learn to expand the number of characteristics. That will allow them to differentiate animals and to use different word forms. The reverse can also happen (= under-generalisation or under-expansion). For example, the word “ball” is only used with the soft, dotted ball that Uncle Jarek brought. Here the child has to learn that everything round that can be thrown is also a ball, regardless of size, colour or origin. Well, almost, of course, this doesn’t mean the orange or decorative glass ball on the living room table should be thrown. You can see, learning meanings, functions and terms is not easy. And we all expand and deepen our vocabulary throughout our lives (I recently learned what is meant by bioenergetics). What is the last word you learnt?

When acquiring new words (i.e., expanding vocabulary breadth) and adding information to a term (i.e., expanding vocabulary depth), parents and caregivers can make an important contribution. For example, we learn that there is more than just one bear, but koala bears, panda bears, polar bears (vocabulary breadth) and we can gather more information about koala bears. For example, I just read that koalas sleep up to 20 hours to conserve energy, which is even longer than sloths.

If you would like to learn more about how you can help your child gain more words and deeper knowledge, check out episode 3 and episode 4 of our podcast Logopädie kompakt.

Apple or Pink Lady? – hierarchies of lexical entries

When we talk to our children, we ask ourselves which words we should use and which words they are able to understand. In the beginning, words mainly belong to the basic level of a category. They are suitable because they can be grasped or experienced well. For example, you can touch an apple, smell it, eat it. Explaining why some of them are called Pink Lady becomes more difficult (hm, I wonder who came up with that name?!). We learn these sub-terms later, incompletely, or never …. I can’t think of any other apple varieties besides Pink Lady, Granny Smith and Gala.

The overall terms also come later (such as vehicles). when we know a larger range of words and more word characteristics we must sort them into categories. Until our dryer broke down, I didn’t know the difference between an exhaust air dryer, a condensation dryer, and a heat pump dryer either. And I’m sure I’ll forget the different again very quickly. Because the frequency of how often we use a word and the motivation to store this word in our lexicon play an important role in memorising new terms. I wish I shared my son’s motivation to learn all the characters of Thomas the Tank Engine. In addition, our lexicons grow very individually, depending on the things and people that surround us and what experiences we have. Or who would have thought that in 2020 even two-year-olds would have the word (corona)virus and face mask in their vocabulary.

Pigeon or flamingo? – what’s in your lexicon?

As already mentioned, we remember words for things that are part of our environment and from the experiences we have. When you close your eyes and imagine a tree, what do you see? What does the tree look like? My guess is that it is something like a chestnut, fir, or the cherry tree from the garden. Most likely, it’s a type of tree that is common in our latitudes and that you see regularly.

The answer would certainly be different if we asked people in Egypt or Bali. We call these typical representatives of a category prototypes. Generally, children first learn the prototypes of their environment and gradually expand their categories to include more specific representatives.

Dog, barking or cuddly? What word categories are stored in the lexicon?

Earlier I talked a lot about naming and learning objects (nouns, like ball). But a variety of other word classes are also learned. For example, interactive words are important at the beginning, we greet each other with “hello” and answer questions with “yes” (or much more often with “no” – I don’t want to know how many times a day my children hear or use that word). Names of people we know are also important, names of family members, nursery mates or toy characters also make an appearance (whose children have Chase, Rubble, Skye and Marshall from Paw Patrol firmly anchored in their vocabulary?). Onomatopoeia should not be forgotten either. An acquaintance of mine was concerned that her child didn’t speak many words at the age of 2 years and worried that he was still using “tatütata” to name the fire brigade. She was relieved to hear that this could be considered a word that her son had stored in his lexicon. Relational words like “there” and “on” or “to” are also often used when children interact with us. They help them and us to describe the environment and relate things to each other. Interjections (or exclamation words) can also be observed. Ragnar, when he was still in an English nursery, came home early with the exclamation “oh dear” and found many opportunities to use it. I, on the other hand, always have to control myself to prevent unwanted exclamations such as “oh sh…eibenkleister” from finding their way into my children’s vocabulary (when Ragnar tried to unsuccessfully put one block on top of another and verbally accompanied this with “bloody hell”, my alarm bells rang and I knew it was time to better control my swearing). Although nouns dominate at first, other word classes are learnt over time as well, including adjectives like “big” or “tired”, and of course verbs. In the beginning, so-called GAP (general-all-purpose) verbs are often used. Many different actions and situations can be verbalised with “have, give, make, come”. However, other verbs are necessary to describe actions in everyday life more precisely (“daddy dance”) and to communicate wishes (“eat apple”). Tips on how to create communicative situations and expand your children’s vocabulary can be found in our podcast Logopädie kompakt episode 3 and episode 4.

Vocabulary explosion – when language development really takes off

After the little rascals have had a hard time acquiring words, a significant increase in the number of words follows. It is generally assumed that children can speak about 50 words at 18 months, and about 200 words at 2 years.

Suddenly, children pick up words with ease, after hearing them a couple of times. So be careful what words you present to your loved ones :-). My friend was taken aback when her daughter kept happily repeating the word “garlic press” after an afternoon of cooking with Aunt Blanca (my little word-learning experiment was a success ;-)).

If you are stressed after reading these guidelines and think “gee, we’ll never get to 50 or 200 words in our lifetime”, remember, there are many individual learning trajectories, with some children you can observe a rapid increase in words, with others a gradual linear or staircase pattern can be observed (see Kauschke, 2015, for an overview). Nevertheless, it is worth paying attention to whether children show an increase in words, as studies have shown that early vocabulary acquisition is closely related to later word acquisition and grammar development (Rowe et al., 2012). Thus, an expanded vocabulary enables the child to combine words and produce first multi-word utterances. Around the 2nd year of life children start combining words (Szagun, 2007).

What does she mean? Unintelligible speech

I talked a lot about the different words that children produce, but what about the pronunciation? Often, we stand in front of our children guessing and trying to decipher what they are trying to tell us. I picture Thorvi when she realises, I haven’t understood her. She repeats the word again and again. She gets louder, slowly resentment grows. Finally, she gets angry and desperate. Phew, these are difficult moments, and I feel sorry every time I notice how upset she is. I then try to infer what she means from the context and repeat what I have understood (e.g., “we see a rabbit here in the book, do you mean the rabbit?”). In our podcast 3 of Logopädie kompakt we talk about such contexts and what you can do to keep the communication going.

These moments are stressful and frustrating, but they are normal at that age and nothing to worry about. Intelligibility improves over time and usually by the age of 3 or 4 children can articulate more clearly. What we need to keep in mind though is that we understand our little ones better than other caregivers (such as educators) or strangers. In addition, intelligibility depends on the situation. If we are sitting on the carpet playing a fishing game, it is more likely that we will understand what the child is trying to say. Conversely, when we are doing our shopping at the supermarket, it is almost impossible to figure out which of the many colourful things is being talked about (moreover, we have to tune out all the background noise that makes it difficult to hear what is being said, see e.g. McLeod, 2020). If you want to get an overview of your child’s intelligibility, you can download the following intelligibility rating scale free of charge (Intelligibility in Context Scala- available in a number of languages).

If you use the scale, please note the following: The score resulting from the assessment is for guidance only and does not serve as a diagnostic score; the scale cannot be used to assess whether the level of intelligibility requires therapeutic intervention. If you are unsure whether your child has unintelligible speech, consult your paediatrician, or seek advice from a Speech and Language Therapist.

How children simplify speech

But what makes children’s speech so difficult to understand? Firstly, stress patterns can differ (this can especially be the case when children acquire several languages and word stress differs across the languages). Secondly, we distinguish different processes which simplify word forms. I have already mentioned the classic example of “banana” becoming “Nana”. Here the word structure is affected. A whole syllable is omitted. These types of utterances (so called structural processes) show up especially at the beginning of language development. Syllable structure can be affected as well, i.e. parts of a syllable are omitted or sounds are added: “tree” becomes “tee”, “telephone” becomes “telepho” or “flower” becomes “lower”. Substitution processes can be observed as well. For example, one sound can be replaced by another (also called systemic processes). A very common substitution is the fronting of “k” to “t”, the “cup” becomes “tup” or the “carrot” becomes “tarrot”.

Sounds within a word or within an utterance also frequently influence speech (this is called assimilation). For example, “hammer” becomes “mammer” because the “m” at the end is transferred to the beginning of the word and replaces the “h”.


In this blog we learnt that:

Babies go through 2 babbling stages (the last one is influenced by the child’s home language
First words occur around the age of 12 months, around 18 months children speak 50 words, at 2 they use around 200 words. That is the time when the so-called word explosion takes place and children learn new vocabulary rapidly.
Children show over-generalisation and under-generalisation of words before they refine their lexical categories (learning more words – vocabulary breadth and learn more characteristics about words – vocabulary depth)
Prototypes are followed by more specific terms (apple vs Pink Lady)
Speech can be very unintelligible at the beginning; later children show simplification processes which replace certain sounds or reduce the syllable structure of words.

So, I’ve thrown quite a few theories and technical terms at you. Nevertheless, I hope you found it interesting to get an outline of this first period of language development.

After all those facts, if you want to know how you can support your little ones, check out the following blog. And here are 3 things you should think about when reading a book to your child.

All the best,



Fasolo, M., Majorano, M., & D’Odorico, L. (2008). Babbling and first words in children with slow expressive development. Clinical Linguistics and Phonetics, 22(2), 83-94. 

Fox-Boyer, A., & Schäfer, B. (2015). Die phonetisch-phonologische Entwicklung von Kleinkindern. In S. Sachse (Ed.), Handbuch Spracherwerb und Sprachentwicklungsstörungen – Kleinkindphase (pp. 39-62). München: Elsevier.

Graf Estes, K., Gluck, S. C.-W., & Grimm, K. J. (2016). Finding patterns and learning words: Infant phonotactic knowledge is associated with vocabulary size. Journal of Experimental Child Psychology, 146, 34-49. doi:http://dx.doi.org/10.1016/j.jecp.2016.01.012

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