What if you said chasi (half) hallel instead of the full hallel on Chanukah?
Shalom, Thank you for your question. There is actually an argument about this issue amongst the Rabbis. In the work Shevet HaLevi (7,62) he rules that one who said half Hallel instead of full Hallel needs to repeat the Hallel, but not the blessings (at the start and end). And this is indeed how the work Ishay Israel (41, 36) rules. However, the Revavot Efraim (4, 105) rules to repeat the Hallel with the blessings. And Rav Kenavisky shilt"ah is quoted as saying that if one has made a break between the half Hallel and the repetition then they probably do need to recite the blessings also. In my humble opinion one should repeat the (full) Hallel with the blessings – unless one already repeated the Hallel without them, in which case, let that recitation (without the blessings) suffice. Hanukah Semach!