Hi, welcome to silkysteps
Page 64 of the
cache handbook looks at 12-19yr milestones in communication as their development of a faster, legible style of handwriting, a growing ability to communicate maturely and have an understanding of abstract language such as idioms, figurative language and metaphors. Ability to process texts and abstract meaning, relate word meanings and contexts, understand punctuation, and form ever more complex syntactic structures.
In another, it mentions how children and young people in this age group may be reluctant to communicate/ask adults for help directly, maybe prefering to source the information they need annonymously in places such as the internet or through peers.
Ages and stages 11 - 17 on talkingpoint is useful
http://www.silkysteps.com/forum/showthread.php?t=11669
If you've access to a copy of the
Child development 12- 19 handbook it has good reading.
Hth xx