How Languages are Learned 4th edition. Nina Spada

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.