Translation:Eighteen, nineteen, twenty.
This is a long standing bug (I'm sorry to say) and after numerous attempts to correct it we have not managed to do so. If you get the sentence again just give them what they want....lack of spaces between the words.
Since this is a technical error you can report it to Duo Help Center page: https://support.duolingo.com/hc/en-us
Thanks for your notification and your patience.
I guess this is the usual problem with Type
what you hear exercises. As far as we know the DuoBot accepts only the exact words given above in the original sentence, not variants of these words, e.g. only δεκαο
χτώ, not δεκαο
κτώ. In this case you can actually hear the difference, but it does get more problematic with pairs like τρένο/τραίνο, which sound the same.
I have recently reconstructed these sentences so as to: include the spaces and add a variety of spellings. I thought I had nailed it. I cannot believe my eyes. It's like some "magic fabric" that returns to its original shape. Looks like we'll need to do some major surgery and then wait for the new tree to get this right. I'm sorry.