"Did the Terrans aid you? Yes. They aided us."
Translation:lIboQ'a' tera'nganpu'? HISlaH. nuboQ.
There is intended to be a hint lIboQ'a' for the three-word combination "Did ... aid you?", which should appear if you hover over any of those three words.
If it doesn't appear, I'm not sure whether this is something we have influence over -- it may be time for a Duolingo bug report ( https://support.duolingo.com/hc/en-us/articles/204728264-How-do-I-report-a-bug- )
If you do see that phrase hint but also see the hints for individual words, then everything is working as it should -- remember that hints may contain translations that are not applicable for the given sentence but only when that word occurs in some other context, in this case for "aid" = boQ and "you" = tlhIH; Da-; SoH; bI-; ....