How many periods of time do the researchers study on children’s language development?

 Lecturer
Today, in our series of lectures on human language, we are going to be
looking at the way in which children acquire language. The study of how
people learn to speak has proved to be one of the most fascinating, important
and complex branches of language study. So let's look at these three features
in turn. Firstly--why is it fascinating? This stems from the natural interest
people take in the developing abilities of young children. People are fascina-
ted by the way in which children learn, particularly their own children!
Secondly, it is important to study how we acquire our first language,
because the study of child language can lead us to a greater understanding of
language as a whole. The third point is that it's a complex study because of
the enormous difficulties that are encountered by researchers as soon as they
attempt to explain language development, especially in the very young
child.
In today's lecture we will cover a number of topics. We will start by
talking about research methods. There are a number of ways that researchers
have investigated children's language and these include the use of diaries,
recordings and tests, and we'll be looking at how researchers make use of
these various methods. We will then go on to examine the language learning
process, starting with the development of speech in young infants during the
first year of life. This is the time associated with the emergence of the skills
of speech perception, in other words, an emergence of the child's awareness
of his or her own ability to speak. We will continue with our examination of
the language learning process, this time by looking at language learning in
the older child, that is in children under five. As they mature, it is possible
to begin analysis in conventional linguistic terms, and so in our analysis we
will look at phonological, grammatical and semantic development in pre-
school children.
In the second part of the talk I would like to review some educational
approaches to the question of how linguistic skills can be developed. In other
words, how can we assist the young child to learn language skills at school?
Initially we will look at issues that arise in relation to spoken language; we
will then look at reading and review a number of approaches that have been
proposed in relation to the teaching of reading. Finally we will conclude
today's talk with an account of current thinking about the most neglected
area of all, the child's developing awareness of written language.