1) SAYING HAVDALAH IN "HAVINENU"
QUESTION: The Gemara states that a person may not say "Havinenu," the abridged version of Shemoneh Esreh, on Motza'ei Shabbos because he cannot insert the Havdalah prayer ("Atah Chonantanu") into Havinenu. The Gemara asks, why can he not just recite an abridged version of Havdalah in the abridged version of Shemoneh Esreh? The Gemara leaves this question unanswered.
Is there any answer that can be suggested for this question?
ANSWER: RABEINU YONAH suggests that the insert of Havdalah is only a prayer and not a blessing of its own (hence it is included in the blessing of "Chonen ha'Da'as"). If one were to say a shortened version of Havdalah in Havinenu it would appear to be a real blessing that was abbreviated for insertion into Havinenu, since Havinenu is composed of abridged blessings. Therefore, we cannot insert a mention of Havdalah into Havinenu.
RAV CHAIM SOLOVEITCHIK applies this teaching of Rabeinu Yonah to explain why we do not mention Chanukah and Purim ("Al ha'Nisim") in the blessing of Berachah me'Ein Shalosh ("Al ha'Michyah"), even though we make mention of every other festival in that blessing. We know that the blessing of Al ha'Michyah is an abridged form of Birkas ha'Mazon. If, in the full version of Birkas ha'Mazon, we mention Al ha'Nisim, why do we not mention it in the abridged version?
Rav Chaim answers that we cannot mention Al ha'Nisim in the abridged version because anything added to an abridged prayer looks as though it, itself, was a blessing in its original form, as Rabeinu Yonah explains with regard to Havdalah, and it would look as though Al ha'Nisim was a blessing originally, which it was not.
However, according to this, why do we mention Shabbos ("Retzeh") and Rosh Chodesh ("Ya'aleh v'Yavo") in Al ha'Michyah when those prayers are also not blessings in the full Birkas ha'Mazon?
Rav Chaim explains that those prayers sometimes are blessings in the full Birkas ha'Mazon. If a person forgets to say "Retzeh" and remembers after the blessing of "Boneh Yerushalayim" but before beginning the next blessing, he recites a short blessing in lieu of "Retzeh" that mentions Shabbos (see the Gemara later on 49a, and Shulchan Aruch OC 188:6). Similarly, if a person forgets to say "Ya'aleh v'Yavo," he recites a short blessing that mentions that special day. For that reason we include an abridged mention of Shabbos and Rosh Chodesh in Al ha'Michyah because they indeed are abridged blessings.
Rav Chaim further explains that this is the reason why we mention Shabbos and Rosh Chodesh after the words "u'Veneh Yerushalayim" in Al ha'Michyah, while in Birkas ha'Mazon we say them before the blessing of "Boneh Yerushalayim." Since these short mentions are not abridged versions of "Retzeh and "Ya'aleh v'Yavo," but rather abridged versions of the blessings of Shabbos and Rosh Chodesh, which are said after "Boneh Yerushalayim," they are said after "u'Veneh Yerushalayim" in Al ha'Michyah!