Q1. fluently, words understanding, prononciation,idiom use and etc..
Q2. 这个是谐音分类,比较难回答,中文都不太会.In my own opinion, the Homonyms can classify as brief in use (for example: 4 instead FOR, CU means see you, 2 sounds like TOO) and just for fun (for example, in chinese we use sea turtle instead of the people come back from overseas)
Q3. words is short and brief, but the its meaning can explan the word's details information and available in which situation.