Language is a system of symbols and rules that is used for meaningful communication. A system of communication has to meet certain criteria in order to be considered a language: 1  A language uses symbols, which are sounds, gestures, or written characters that represent objects, actions, events, and ideas. A language uses symbols, which are sounds, gestures, or written characters that represent objects, actions, events, and ideas. 2  Symbols enable people to refer to objects that are in another place or events that occurred at a different time.
Also remember that children between the ages of 6 and 18 months can normally move up or down on their percentiles, but older children should follow their growth curve fairly closely. Answers to examples: 1) 50th percentile, 2) 10th percentile, 3) 50th percentile, 4) 75th percentile, 5) about the 15th percentile.
By age 2, growth in height usually continues at a fairly steady rate of about 2Â½ inches (6 centimeters) per year until adolescence. No child grows at a perfectly steady rate throughout this period of childhood, though. Weeks or months of slightly slower growth alternate with mini growth spurts in most children. Kids actually tend to grow a bit faster in the spring than during other times of the year! A major growth spurt happens at the time of puberty, usually between 8 to 13 years of age in girls and 10 to 15 years in boys. Puberty lasts about 2 to 5 years.