I used " till" instead of " until" but it was considered wrong. Why?! The two terms are synonyms and interchangeable. Thanks.
"'till" or "'til" is considered a slang term and its probably the reason why DL considers it wrong. If they accept that, then they should accept "ain't" as a suitable translation for "non è" or "non ha," of as well as many other slang terms.
TIll is a perfectly good English word dating back to at least 1200 according to this article http://minnesota.publicradio.org/radio/podcasts/grammar_grater/archive/2008/11/13/. It should be acceptd by DL