"She is coming to swim once."
Translation:Zij komt een keer zwemmen.
I really don't understand the meaning of this sentence. Does the once sound less awkward in Dutch? Unless this girl has a history of overstaying her welcome with multiple swim sessions, I can't understand why you would need the word "once".
It's very natural in Dutch. Maybe it would be better in English to use some time instead of once, I think that would have the same meaning as the Dutch sentence.
Thank you. As it stands the English translation is just...such a very odd sentence.
It is hard to say why not, but it just isn't. Grammatically it does not make sense.
You either omit the 'te' as in "Zij komt een keer zwemmen" (She will come some time to swim) or add 'om' as in "Zij komt een keer om te zwemmen" (She will come some time to swim). The second is more a statement of purpose (the swimming) while the first is just describing the action.
Can someone tell me why "één keer" is wrong please? I thought that this would mean "one time", i.e. once whereas "een keer" would mean "a time".
Well technically you are right. since there is not always a rigid distinction between 'een keer' and 'één keer' (note however that while spoken there is a very distinct difference in emphasis!)
So, 'Zij komt een keer zwemmen' could mean either 'She will come to swim sometime' or 'She will come to swim one time'.
And 'Zij komt één keer zwemmen' could only mean 'She will come to swim one time'.
In English you wouldn't use "once" if you didn't mean to emphasize that something happens only one single time. Translating "once" with "een keer" instead of "één keer" seems to lose that emphasis.