Today we are going to learn the second type of word – Function Words (虚词).
虚 in Chinese means empty or void, which is opposite of 实.
Function words（虚词） serve only grammatical functions. They has no meaning by themselves. Function words（虚词） have to be used together with Notional Words （实词）to construct a meaningful sentence or phrase.
虚词 are much smaller in number but frequently used.
In Chinese, function words （虚词） are divided into six main categories: