Same impression -

The kid's vacabulary increased trmendously after junior middle school, for me, I feel that from my son, I discovered that although he just entered grade 9, his vacabulary is far beyond my match, he read so many novels and I couldn't catch up at all (thinking of that would make one upset), I guess he get acquainted with words from daily communication and reading ... however, one thing missing for him is the usage of them in writing.