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One remarkable thing about first language acquisition is the high degree of similarity in the early language of children all over the world. Researchers have described developmental sequences for many aspects of first language acquisition. The earliest vocalizations are simply the involuntary crying that babies do when they are hungry or uncomfortable. Soon, however, we hear the cooing and gurgling sounds of contented babies, lying in their beds looking at fascinating shapes and movement around them. Even though they have little control over the sounds they make in these early weeks of life, infants are able to hear subtle differences between the sounds of human languages. Not only do they distinguish the voice of their mothers from those of other speakers, they also seem to recognize the language that was spoken around their mother before they were born. Furthermore, in cleverly designed experiments, researchers have demonstrated that tiny babies are capable of very fine auditory discrimination. For example, they can hear the difference between sounds as similar as ‘pa’ and ‘ba’.

Janet Werker, Patricia Kuhl, and others have used new technologies that allow us to see how sensitive infants are to speech sounds. What may seem even more remarkable is that infants stop making distinctions between sounds that are not phonemic in the language that is spoken around them. For example, by the time they are a year old, babies who will become speakers of Arabic stop reacting to the difference between ‘pa’ and ‘ba’ which is not phonemic in Arabic. Babies who regularly hear more than one language in their environment continue to respond to these differences for a longer period (Werker, Weikum, and Yoshida 2006). One important finding is that it is not enough for babies to hear language sounds from electronic devices. In order to learn – or retain – the ability to distinguish between sounds, they need to interact with a human speaker (Conboy and Kuhl 2011). The Internet abounds with remarkable videos of infants reacting to language sounds.

Whether they are becoming monolingual or bilingual children, however, it will be many months before their own vocalizations begin to reflect the characteristics of the language or languages they hear and longer still before they connect language sounds with specific meaning. However, by the end of their first year, most babies understand quite a few frequently repeated words in the language or languages spoken around them. They wave when someone says ‘bye-bye’; they clap when someone says ‘pat-a-cake’; they eagerly hurry to the kitchen when ‘juice and cookies’ are mentioned.

At 12 months, most babies will have begun to produce a word or two that everyone recognizes. By the age of two, most children reliably produce at least 50 different words and some produce many more. About this time, they begin to combine words into simple sentences such as ‘Mommy juice’ and ‘baby fall down’. These sentences are sometimes called ‘telegraphic’ because they leave out such things as articles, prepositions, and auxiliary verbs. We recognize them as sentences because, even though function words and grammatical morphemes are missing, the word order reflects the word order of the language they are hearing and the combined words have a meaningful relationship that makes them more than just a list of words. Thus, for an English-speaking child, ‘kiss baby’ does not mean the same thing as ‘baby kiss’. Remarkably, we also see evidence, even in these early sentences that children are doing more than imperfectly imitating what they have heard. Their two- and three-word sentences show signs that they can creatively combine words. For example, ‘more outside’ may mean ‘I want to go outside again.’ Depending on the situation, ‘Daddy uh-oh’ might mean ‘Daddy fell down’ or ‘Daddy dropped something’ or even ‘Daddy, please do that funny thing where you pretend to drop me off your lap.’

As children progress through the discovery of language in their first three years, there are predictable patterns in the emergence and development of many features of the language they are learning. For some language features, these patterns have been described in terms of developmental sequences or ‘stages’. To some extent, these stages in language acquisition are related to children’s cognitive development. For example, children do not use temporal adverbs such as ‘tomorrow’ or ‘last week’ until they develop some understanding of time. In other cases, the developmental sequences seem to reflect the gradual acquisition of the linguistic elements for expressing ideas that have been present in children’s cognitive understanding for a long time. For example, children can distinguish between singular and plural long before they reliably add plural endings to nouns. Correct use of irregular plurals (such as ‘feet’) takes even more time and may not be completely under control until the school years.

Grammatical morphemes

In the 1960s, several researchers focused on how children acquire grammatical morphemes in English. One of the best-known studies was carried out by Roger Brown and his colleagues and students. In a longitudinal study of the language development of three children (called Adam, Eve, and Sarah) they found that 14 grammatical morphemes were acquired in a similar sequence. The list below (adapted from Brown’s 1973 book) shows some of the morphemes they studied.

present progressive -ing (Mommy running)

plural -s (two books)

irregular past forms (Baby went)

possessive -s (Daddy’s hat)

copula (Mommy is happy)

articles the and a regular past -ed (she walked)

third person singular simple present -s (she runs)

auxiliary be (he is coming)

Brown and his colleagues found that a child who had mastered the grammatical morphemes at the bottom of the list had also mastered those at the top, but the reverse was not true. Thus, there was evidence for a ‘developmental sequence’ or order of acquisition. However, the children did not acquire the morphemes at the same age or rate. Eve had mastered nearly all the morphemes before she was two-and-a-half years old, while Sarah and Adam were still working on them when they were three-and-a-half or four.

Brown’s longitudinal work was confirmed in a cross-sectional study of 21 children. Jill and Peter de Villiers (1973) found that children who correctly used the morphemes that Adam, Eve, and Sarah had acquired late were also able to use the ones that Adam, Eve, and Sarah had acquired earlier. The children mastered the morphemes at different ages, just as Adam, Eve, and Sarah had done, but the order of their acquisition was very similar.

Many hypotheses have been advanced to explain why these grammatical morphemes are acquired in the observed order. Researchers have studied the frequency with which the morphemes occur in parents’ speech, the cognitive complexity of the meanings represented by each morpheme, and the difficulty of perceiving or pronouncing them. In the end, there has been no simple satisfactory explanation for the sequence, and most researchers agree that the order is determined by an interaction among a number of different factors.

To supplement the evidence we have from simply observing children, some carefully designed procedures have been developed to further explore children’s knowledge of grammatical morphemes. One of the first and best known is the so-called ‘wug test’ developed by Jean Berko Gleason (1958). In this ‘test’, children are shown drawings of imaginary creatures with novel names or people performing mysterious actions. For example, they are told, ‘Here is a wug. Now there are two of them. There are two____’ or ‘Here is a man who knows how to bod. Yesterday he did the same thing. Yesterday, he____’. By completing these sentences with ‘wugs’ and ‘bodded’, children demonstrate that they know the patterns for plural and simple past in English. By generalizing these patterns to words they have never heard before, they show that their language is more than just a list of memorized word pairs such as ‘book/books’ and ‘nod/nodded’.

ACTIVITY Try out the ‘wug’ test

A web search for ‘wug test’ will turn up many examples of the pictures and the text created for this landmark research. If you know some English-speaking children under the age of five years, try using the test with them.

1 What similarities and differences do you notice among the children at different ages?

2 Which grammatical morphemes do they find easy and which ones are more difficult?

The acquisition of other language features also shows how children’s language develops systematically, and how they go beyond what they have heard to create new forms and structures.

Negation

Children learn the functions of negation very early. That is, they learn to comment on the disappearance of objects, to refuse a suggestion, or to reject an assertion, even at the single word stage. However, as Lois Bloom’s (1991) longitudinal studies show, even though children understand these functions and express them with single words and gestures, it takes some time before they can express them in sentences, using the appropriate words and word order. The following stages in the development of negation have been observed in the acquisition of English. Similar stages have been observed in other languages as well (Wode 1981).

Stage 1

Negation is usually expressed by the word ‘no’, either all alone or as the first word in the utterance.

No. No cookie. No comb hair.

Stage 2

Utterances grow longer and the sentence subject may be included. The negative word appears just before the verb. Sentences expressing rejection or prohibition often use ‘don’t’.

Daddy no comb hair. Don’t touch that!

Stage 3

The negative element is inserted into a more complex sentence. Children may add forms of the negative other than ‘no’, including words like ‘can’t’ and ‘don’t’. These sentences appear to follow the correct English pattern of attaching the negative to the auxiliary or modal verb. However, children do not yet vary these forms for different persons or tenses.

I can’t do it. He don’t want it.

Stage 4

Children begin to attach the negative element to the correct form of auxiliary verbs such as ‘do’ and ‘be’.

You didn’t have supper. She doesn’t want it.

Even though their language system is by now quite complex, they may still have difficulty with some other features related to negatives.

I don’t have no more candies.

Questions

The challenge of learning complex language systems is also illustrated in the developmental stages through which children learn to ask questions.

There is a remarkable consistency in the way children learn to form questions in English. For one thing, there is a predictable order in which the ‘wh- words’ emerge (Bloom 1991). ‘What’ is generally the first wh- question word to be used. It is often learned as part of a chunk (‘Whassat?’) and it is some time before the child learns that there are variations of the form, such as ‘What is that?’ and ‘What are these?’.

‘Where’ and ‘who’ emerge very soon. Identifying and locating people and objects are within the child’s understanding of the world. Furthermore, adults tend to ask children just these types of questions in the early days of language learning, for example, ‘Where’s Mommy?’ or ‘Who’s that?’

‘Why’ emerges around the end of the second year and becomes a favourite for the next year or two. Children seem to ask an endless number of questions beginning with ‘why’, having discovered how effectively this little word gets adults to engage in conversation, for example, ‘Why that lady has blue hair?’

Finally, when the child has a better understanding of manner and time, ‘how’ and ‘when’ emerge. In contrast to ‘what’, ‘where’, and ‘who’ questions, children sometimes ask the more cognitively difficult ‘why’, ‘when’, and ‘how’ questions without understanding the answers they get, as the following conversation with a four-year-old clearly shows.

The ability to use these question words is at least partly tied to children’s cognitive development. It is also predicted in part by the questions children are asked and the linguistic complexity of questions with different wh- words. Thus it does not seem surprising that there is consistency in the sequence of their acquisition. Perhaps more surprising is the consistency in the acquisition of word order in questions. This development is not based on learning new meanings, but rather on learning different linguistic patterns to express meanings that are already understood.

Stage 1

Children’s earliest questions are single words or simple two- or three-word sentences with rising intonation:

Cookie? Mommy book?

At the same time, they may produce some correct questions – correct because they have been learned as chunks:

Where’s Daddy? What’s that?

Stage 2

As they begin to ask more new questions, children use the word order of the declarative sentence, with rising intonation.

You like this? I have some?

They continue to produce the correct chunk-learned forms such as ‘What’s that?’ alongside their own created questions.

Stage 3

Gradually, children notice that the structure of questions is different and begin to produce questions such as:

Can I go?

Are you happy?

Although some questions at this stage match the adult pattern, they may be right for the wrong reason. To describe this, we need to see the pattern from the child’s perspective rather than from the perspective of the adult grammar. We call this stage ‘fronting’ because the child’s rule seems to be that questions are formed by putting something (a verb or question word) at the ‘front’ of a sentence, leaving the rest of the sentence in its statement form.

Is the teddy is tired? Do I can have a cookie?

Why you don’t have one? Why you catched it?

Stage 4

At Stage 4, some questions are formed by subject–auxiliary inversion. The questions resemble those of Stage 3, but there is more variety in the auxiliaries that appear before the subject.

Are you going to play with me?

At this stage, children can even add ‘do’ in questions in which there would be no auxiliary in the declarative version of the sentence.

Do dogs like ice cream?

Even at this stage, however, children seem able to use either inversion or a wh-word, but not both (for example, ‘Is he crying?’ but not ‘Why is he crying?’

Therefore, we may find inversion in yes/no questions but not in wh- questions, unless they are formulaic units such as ‘What’s that?’

Stage 5

At Stage 5, both wh- and yes/no questions are formed correctly.

Are these your boots?

Why did you do that?

Does Daddy have a box?

Negative questions may still be a bit too difficult.

Why the teddy bear can’t go outside?

And even though performance on most questions is correct, there is still one more hurdle. When wh- words appear in subordinate clauses or embedded questions, children overgeneralize the inverted form that would be correct for simple questions and produce sentences such as:

Ask him why can’t he go out.

Stage 6

At this stage, children are able to correctly form all question types, including negative and complex embedded questions.

Passage through developmental sequences does not always follow a steady uninterrupted path. Children appear to learn new things and then fall back on old patterns when there is added stress in a new situation or when they are using other new elements in their language. But the overall path takes them toward a closer and closer approximation of the language that is spoken around them.