I cut down a certain sweet tree and used the wood to make my BOWLing ball.
|なにがし ( かのｘｘｘ )||
：a certain ｘｘｘ ; it also has the connotation of 'undisclosed', like Dick Cheny's undisclosed location.
a certain ★☆☆☆☆
PREFIX: you can put it before any noun, with no particles in between, for example:
某国： ぼうごく:a certain country,
某地：ぼうち： an undisclosed location,
某猿： ぼうさる :a certain monkey.