Children’s vocabulary organization

The type frequency of sematic categories provides some findings. In general, the category of people, tools, animals, and food are the dominant categories in each age.

Besides, vehicle nouns and locations are major nouns as well. What is more, the category of abstract nouns becomes a main category in 43-48 months. On the contrary, the categories of numerals, shapes, furniture, and colors appear less in children’s speech.

Children have few pronouns in 37-42 months and few natural phenomena nouns in 43-48 months. A continued rising or falling proportion may be viewed as a steady tendency of development. Therefore, a decreasing proportion is found in people and animals until 42 months. The proportion of food rises in 25-30 months, but it keeps falling until 48 months. Meanwhile, an increasing proportion is found in clothing and abstract nouns until 42 months, but it decreases in 43-48 months. The proportion of spatial words keeps rising across all age stages. Other categories have a fluctuated trend of rising and declining.

As for how often children use nouns of different semantic categories, the categories of people, pronouns, animals, spatial words, and tools are the most frequently used. Children produced vehicles nouns very often in 19-24 months. As for the least frequently used categories, numerals, shapes, furniture, and colors have the lowest

frequency in children’s speech. The category of natural phenomena also has a low frequency in 43-48 months. In terms of a falling trajectory, the use of people and food keeps declining across all stages, and the use of animals also keeps dropping until 42 months. On the contrary, the use of pronouns keeps increasing in all stages, and the use of shapes and abstract nouns remains rising until 37-42 months. Other categories have an unsteady proportion changes.

In summary, the most concrete nouns and nouns which are the closest to children’s life are acquired earlier, such as people, tools, animals, and food, and vehicles. Nouns in these categories are also used frequently. On the other hand, nouns which are abstract and far away from children’s daily life are acquired later and used with a lower frequency, such as numerals, shapes, colors, and nouns of natural phenomena.

Conceptual levels

The results have shown that there are more distinct basic-level words but fewer subordinate and superordinate words in earlier age stages, whereas the numbers of subordinate and superordinate words increase in later age stages. The highest proportions of three levels are 68.1% of basic-level words in 19-24 months, 39.3% of subordinate words in 43-48 months, and 3.1% superordinate words in 31-36 months.

Besides, the proportion change indicates that children acquire relatively more subordinate words in 25-30 months. They increased the proportion of basic-level words and superordinate words in 31-36 months. After 36 months, children increase the proportion of subordinate words and reduce the proportion of basic-level words.

General speaking, when the proportion of basic-level words decreases, the proportion of subordinate words increases, and vice versa. In addition, although the number of noun

differ much.

As for the frequency of using nouns, basic-level words account about 80% noun tokens in children’s speech in all stages. The proportion also reveals that children use more subordinate words in 25-30 months than other stages, but the proportion decreases in later stages. The number and proportion of superordinate words increase before 31-36 months, but the proportion fluctuates after 36 months. In general, although the number of noun tokens of three levels changes in some stages, the changes seem not to differ much, except for subordinate words. Compared with the results of noun types on three conceptual levels, the development trend indicates that although the proportion of basic-level noun types decreases with increasing age, children keep using basic-level words frequently and even a little bit more frequently in later stages. Meanwhile, the proportion of subordinate noun types increases as time goes by, but children reduce the frequency of using subordinate words gradually.

With regard to conceptual levels in semantic categories, three patterns of the word frequency in three conceptual levels were found. It seems that most categories have more basic-level word types than subordinate words, and more subordinate words than superordinate words. The categories are tools, location, natural, clothing, body parts, toys, food, animals, pronouns, furniture, spatial words before 30 months, and abstract nouns. One pattern is that subordinate words outnumber basic-level words, and basic-level words outnumber superordinate words. The categories of people, vehicles, and spatial words after 30 months developed in this way. Three semantic categories, shapes, colors, and numerals, show a trend of more basic-level words than superordinate words, and more superordinate words than subordinate words

Additionally, basic-level words are used with a higher frequency than superordinate and subordinate words in most semantic categories, except for vehicles

after 36 months in which subordinate words is more frequently used than basic-level words. Subordinate words are used with a higher frequency than superordinate words in most semantic categories, except for clothing, tools and toys. Superordinate nouns of clothing, tools and toys are used more often than subordinate words in some stages.