The purpose of this study was to find out how verbal and non-verbal CU's (communication units) of children towards their parents in problem-solving situations change depending on children's ages. I classified their verbal CU's in problem-solving situations into 15 categories based on the meanings, and their non-verbal CU's into 14. The results were as follows :
1) The most common children's CU's in problem-solving situations were spontaneous such as talking to themselves, thus they were not trying to get information from their parents or respond to them. This tendency didn't change from year 1 to year 2.
2) The children showed significantly more frequent CU's relating to offering and collecting information at 2 years old than at 1 year old. This tendency was found both in verbal and nonverbal CU's.