I have some problems understanding the accurate and precise meaning of the expressions following : "water to drink.." Here We understand that water is for drinking by someone.The action "drink" is supposed to be done by someone or a living entity.What confuses my mind is that what become of the meaning when we say " water to be drunk".. "icecream to be eaten" ". Now as for my second question which is related to what I said above in a way.I gave examples in which noun that comes before "to" is sth not living.My question is that :a husband to be, a girl to marry , a woman to sacrifice , student to get high mark"... Is the way of usage of "to" correct here? The noun before to is sometimes subject and object of the verb that follows "to".How can we differentiate them?
If so, doesn't it contrast with the way of usage in my first question? Because , we suppose that the action of "drinking" for example, is done by someone who is NOT mentioned in the expression.But here , the action(mary,sacrife,be..) is supposed to be done directly by a husband , a girl , a women,...? .. Thanks for your lightining answers in advance..