"That is no age!"
Translation:Det är ingen ålder!
"That is not old!" conveys the intended meaning but fails to follow the grammatical construction in this Swedish sentence. In Swedish, the word "ålder" is a noun and can be translated into English as "old age," and so this sentence, "Det är ingen ålder!" could be translated as "That is not old age!" or possibly "That is no lifetime!" For example, in my profile photo you can see three generations, my father, me, and my son. My father was just past age 60 when this son was born, but Dad lived to age 86. So, when the photo was taken, his age was "not old age" -- "ingen ålder." In this English phrase, "not" is an adverb modifying the adjective "old," but in the Swedish equivalent, "ingen ålder," the negation applies directly to a noun, and so it is an adjective. Therefore, this English translation, taking into account the need for three words for an accurate translation, respects both the grammar and the meaning of "Det är ingen ålder!"
See the various translations for "ålder" here:
The exact phrase "that's no age" has over 18,000 results on Google - from books, from newspapers, from informal sources. They all use it in the exact same way as in this sentence. It appears that a very large portion of the English-speaking knows exactly what it means.
Look, I agree that it's not a good fit for the course and I have argued in other threads that it should be removed from the next tree (not the current one - because of technical difficulties related to doing so). But it is not a "nonsense translation in English" - lots of native speakers use it.
I have to say that in most of the examples you provide here the sentence ends with "at all" which certainly makes it sound a lot less odd. It is a rather odd and archaic way of saying this and taken out of context (ie in a single sentence in a lesson like this) really does not make sense. I reckon this might be a good sentence to kill if you can ever work out how to get around the zombie issue. It can make sense but is not a great example sentence...
check that out. I was mistaken, very sorry!