Children who grow up in an environment rich in language are almost always fluent by age three. People deprived of language as children rarely master it as adults, no matter how smart they are or how intensively they’re trained
Dr. Susan Curtiss, Professor of Linguistics at UCLA, who studies the way children learn languages, notes that in language development there is a window of opportunity in which the child learns that first language normally. After this period, the brain becomes slowly less plastic and by the time the child reaches adolescence, the brain cannot develop "richly and normally any real cognitive system, including language."
The four- or five-year old learning a second language is a "perfect model for the idea of the critical period."
When children wait until high school to start studying a foreign language, the job is much harder. The task is a different one than it was for the young child in the sensitive period for language learning. Brain plasticity has been lost, the number of synapses has greatly reduced, and the brain no longer has the same facility to restructure itself that it had when the child was young.
How I think @ 51 months
At this stage, as he uses his words daily, your child will continue to increase his vocabulary, from nouns, pronouns, action words, descriptive words, quantifiers, location words, and question words. He will start to use connecting words such as, and, because, if, and but as their vocabulary increases. He will begin to start conversations by saying “You know what?”. Or “Guess what?” He is so excited to speak that sometimes he has trouble waiting for his turn to speak in the conversation.
Motor Development: Gross Motor Skills
• I can move freely and with pleasure and confidence in a range of ways, such as slithering, shuffling, rolling, crawling, walking, running, jumping, skipping, sliding and hopping
• I can mount stairs, steps or climbing equipment using alternate feet
• I can walk downstairs, two feet to each step while carrying a small object
Motor Development: Fine Motor Skills
• I can use fork, spoon, and (sometimes) a table knife
• I usually can care for my toilet needs
Language and Thinking Development
• I can tell longer stories
• I can better understand the concept of time
• I know about things used every day in the home (money, food, appliances)
Social and Emotional Development
• I want to please friends
• I want to be like my friends
• I am more likely to agree to rules
Disclaimer: This presents an overview of child development. It is important to keep in mind that the time frames presented are averages and some children may achieve various developmental milestones earlier or later than the average but still be within the normal range of development. This information is presented to help parents understand, at a high level, what to expect from their child. Any questions/concerns you may have about your child’s development should be shared with your doctor.