Feierabend (German) - expresses the concept you are finished with the work duties for the day and can enjoy your private time with family and friends
Saudade (Portuguese) - a mixture of loneliness, melancholy, sense of loosing part of you feelings, even mixed with a kid of sad joy, while remembering something that is no longer there.
If they were popular enough, we'd say: English does have words for those ideas! They're "feierabend" and "saudade".
Exactly the same as "gesundheit".
Expressing means there is a similar word.
You should compare Orhan Pamuk's treatment with Fernando Pessoa.
Although you might spend far more words on it, and it might be hard to properly capture abstract concepts in another language, these are not examples of concepts that cannot be expressed in English.
From linguistic point of view, I explained them.
Expressing means there is an English word with the same meaning.
We were talking about concepts being "expressable" in any language. Of course many words are not directly translatable (half of Chinese isn't, that isn't news to anybody), so that's not particularly interesting. But you'd be hard pressed to find a concept that is not at least explainable in English.