The end of the middle beracha of the Amida should read ‘…m’kadaysh Yisroel v’hazmanim’. If you left out the word ‘v’hazmanim’ you are not yotzay. (MB2)
When Yom Tov falls out on Shabbos the ending is adjusted to read ‘m’kadaysh haShabbos v’Yisroel v’hazmanim’. If you just ended with ‘m’kadaysh haShabbos’ without mentioning Yom Tov, you do not need to repeat the beracha. (ShA1 — MB7)
In the middle beracha you say Atta V’chartonu, Ya’aleh V’yovo, and V’hasee’aynu. If you forgot the first or second paragraph it is still okay since you did insert the name of the appropriate festival. But if you forgot both and only remembered V’hasee’aynu you are not yotzay. (ShA3 — MB11)
The minhag for Sefardim is to say the whole Hallel with a tzibbur and with a beracha before and after. This occurs on Seder night(s). (ShA4 — MB16)
