sleepyhorse
There are many issue which can cause language acquisition delay, and until the age of maturation (7 - 8 years old) it is not possible to determine whether any child will grow out of these problems as part of their own natural development. We all develop different cognitive skills and abilities at different ages and different rates until the age of maturation.
There are many issues which can cause language development delay, which is why Speech and Language Pathologists have to prove that they have kept up to date with recent research to continue practicing every 3 or 4 years.
Auditory Processing Disorder (APD) and ADD/ ADHD can have similar symptoms especially at a young age, but have very different medical causes.
Those who have APD have a listening disability, not being able to process what they hear, all sound based information which includes speech. We learn to speak by processing what others (parents, siblings, friends, family) say and then reprocessing or reproducing these sounds in our own form of speech. Par of the problems those who have APD experience is processing the gaps between the sounds which can make up a word, or even processing the gap between words. so processing and understanding the verbal language can be difficult, and it does take time to develop the coping strategies such as effective lip reading, and reading body langauge which can help APD work around their listening disability.
Those who have ADD/ADHD have attention problems of a lack of ability to concentrate or focus long enough to process the a wide range of information, which includes sound based information. similar problems as outlined above but due to a different type of cognitive deficit or disorder.
It is possible to have co-morbid (co existing) APD and ADHD, which is even more difficult to diagnose.
These developmental issues have a genetic origin and at least one biological parent will share some of the issues.