Tahanun is omitted upon: Rosh Hodesh, Hanukka, Tu BiShvat, Adar I's 14th and 15th, Purim and Shushan Purim, throughout Nisan's month, Yom HaAtzma'ut, Iyar's 14th (Pesah Sheni), Lag BaOmer, Yom Yerushalayim, from Rosh Hodesh Sivan as far as the day following Shavuot (in Israel as far as 12th of Sivan), Tisha B'Av, Tu B'Av, Erev Rosh HaShana, and from Erev Yom Kippur as far as the day following Simhat Torah (in Israel as far as Rosh Hodesh Marheshvan).
Tahanun is likewise omitted: on a Brit Mila's morning, whether at the place of the brit or wherever the father, Sandak or Mohel is found; when a groom is present (and some say a bride) on his wedding day or through the week of Sheva Berakhot; in a house of mourning.
Hebrew
אֱלֹהֵינוּ וֵאלֹהֵי אֲבוֹתֵינוּ, תָּבוֹא לְפָנֶיךָ תְּפִלָּתֵנוּ, וְאַל תִּתְעַלַּם מִתְּחִנָּתֵנוּ, שֶׁאֵין
אָנוּ עַזֵּי פָנִים וּקְשֵׁי עֹרֶף לוֹמַר לְפָנֶיךָ, יְהוָה אֱלֹהֵינוּ וֵאלֹהֵי אֲבוֹתֵינוּ, צַדִּיקִים
אֲנַחְנוּ וְלֹא חָטָאנוּ, אֲבָל אֲנַחְנוּ וַאֲבוֹתֵינוּ חָטָאנוּ.
Israeli
Eloheinu veilohei avoteinu, tavo lefanecha t'filatenu, ve-al titalam mitechinatenu, she-ein
anu azei fanim ukshei oref lomar lefanecha, Adonai Eloheinu veilohei avoteinu, tzadikim
anachnu velo chatanu, aval anachnu va-avoteinu chatanu.
At each expression, strike the left side of the chest:
Hebrew
אָשַׁמְנוּ, בָּגַדְנוּ, גָּזַלְנוּ, דִּבַּרְנוּ דֹּפִי, הֶעֱוִינוּ, וְהִרְשַׁעְנוּ, זַדְנוּ, חָמַסְנוּ, טָפַלְנוּ שֶׁקֶר,
יָעַצְנוּ רָע, כִּזַּבְנוּ, לַצְנוּ, מָרַדְנוּ, נִאַצְנוּ, סָרַרְנוּ, עָוִינוּ, פָּשַׁעְנוּ, צָרַרְנוּ, קִשִּׁינוּ עֹרֶף,
רָשַׁעְנוּ, שִׁחַתְנוּ, תִּעַבְנוּ, תָּעִינוּ, תִּעְתָּעְנוּ.
Israeli
ashamnu, bagadnu, gazalnu, dibarnu dofi, he-evinu, vehirshanu, zadnu, chamasnu, tafalnu sheker,
ya-atznu ra, kizavnu, latznu, maradnu, ni-atznu, sararnu, avinu, pashanu, tzararnu, kishinu oref,
rashanu, shichatnu, ti-avnu, ta-inu, titanu.
Neh. 9
Hebrew
סָרְנוּ מִמִּצְוֹתֶיךָ וּמִמִּשְׁפָּטֶיךָ הַטּוֹבִים, וְלֹא שָׁוָה לָנוּ. וְאַתָּה צַדִּיק עַל כָּל־הַבָּא
עָלֵינוּ, כִּי־אֱמֶת עָשִׂיתָ, וַאֲנַחְנוּ הִרְשָׁעְנוּ:
Israeli
sarenu mimitzvotecha umimishpatecha hatovim, velo shavah lanu. ve-atah tzadik al kol-haba
aleinu, ki-emet asita, va-anachnu hirshanu:
When praying without a minyan, go on with Lowering the Head on page 144.