Translation:He used to buy dinner and his girlfriend used to eat it.
Ní cheapim é sin. DL always gives me a "pass" if the only thing is a missing fada but it always has reminded me. I've noticed that it doesn't warn when there is an actual mispelling or similar egregious sin. I posted this because there was no error at all, except the missing fada. I'm not at a beginning level either, though I consider myself still a beginner. I have been at level 5 on all exercises for most of a year and merely keep refreshing as they alert me when they are "stale" so that I can retain the vocabulary and grammar in absence of daily conversation.
Sorry I'm getting back to you this late. I'm not sure what is going on then. I only noticed something myself because early on in the course I had been spelling a word a certain way during an exercise and I just kept getting told I gave the correct solution, no pointing out errors. Later, at a higher level of the same exercise I got told I spelt the word (very!) wrong. It made me a bit paranoid and for a while I kept double checking all my answers by entering the discussion section to check against the topic title or given translation.
edit: I just checked something. I just did a refresher exercise and I deliberately spelt a few words wrong (left out a letter). DL totally ignored my errors during "type what you hear" exercises but pointed them out during the other types.
edit 2: I was doing a regular "type what you hear" exercise and I forgot a fada and it also was not pointed out to me.
I think it's just a quirk with those types of exercises. Maybe because there is not enough space in the green bar to give a translation and point out minor mistakes at the same time.