Question

we say that the wick doesn't burn then how does it get reduced and shortened?

Answer 1

Wick does not burn actually because flame isn’t really touching the wick. Flame and wick remain far separated while candle burns.When the candle burns the melting of wax takes place thus this liquid wax releases hydrocarbon gas which burns. This burning actually takes place far enough from the wick since it requires oxygen for combustion which is not sufficient in the vicinity of wick.