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.