늦어서 미안해 (I am sorry for being late) : When we want to apologize for being late to an appointment, we may say “늦어서 미안해”, and then explain the reason why we are late in various ways.
할 수 없지 (There is nothing we can do about it) : The expression “할 수 없지” is used when we give up on something which cannot be solved with our ability or effort.
보기보다 어렵네 (It is harder than it looks) : We say “보기보다 어렵다” when we find out something which looks easy when we watch, but is difficult when we actually do.
It is used when we leave from an appointed place after meeting a person, or when we leave the work place for home.
the Korean Tutor 