necessary, optionaly, prohibited .
	 
	necessary Ҷ must, have to, need to Ѵ.
	 
	 ʴ ~ ؾ߸Ѵ, ~ ؾѴ  ʼ    Ѵ.
	 
	optionaly   μ صǰ  ʾƵ Ǵ  Ѵ.
	 
	 
	 
	 
	do not have to do not need to Ἥ صǰ ص Ǵ ״     ȴ.
	 
	 prohibited  ϸ ȵǴ ݱ  ϴ ̴.
	 
	must not, can not  ϸ ȵǴ     Ѵ.
	 
	 
	 
	 
	   Ƹī necessary, optionaly, prohibited ؾϴ  .
	 
	   Ϸ翡 ѹϰ Ʈ ߶ִ° ̰ ʼ .
	 
	  ܱε Ų 翬 ȭ ص   ˾Ҵµ   .
	 
	 ۿ   ־µ ѱ  ణ ٸ  Ҵ.