Halakhah for Berakhot 1:4
בַּשַּׁחַר מְבָרֵךְ שְׁתַּיִם לְפָנֶיהָ וְאַחַת לְאַחֲרֶיהָ, וּבָעֶרֶב שְׁתַּיִם לְפָנֶיהָ וּשְׁתַּיִם לְאַחֲרֶיהָ. אַחַת אֲרֻכָּה וְאַחַת קְצָרָה. מָקוֹם שֶׁאָמְרוּ לְהַאֲרִיךְ, אֵינוֹ רַשַּׁאי לְקַצֵּר. לְקַצֵּר, אֵינוֹ רַשַּׁאי לְהַאֲרִיךְ. לַחְתֹּם, אֵינוֹ רַשַּׁאי שֶׁלֹּא לַחְתֹּם. וְשֶׁלֹּא לַחְתֹּם, אֵינוֹ רַשַּׁאי לַחְתֹּם:
In the morning he recites two benedictions before it (the Shema) ["yotzer or" and "ahavah"], and one after it ["emeth veyatziv"]; and in the evening he recites two benedictions before it ["ma'ariv aravim" and ahavath olam"] and two after it ["emeth ve'emunah" and "hashkiveinu"], one long and the other short. [This refers to the two benedictions before it. "Yotzer or" is long, opening with "Baruch" and closing with "Baruch," as does "ma'ariv aravim." "Ahavah" is short, closing with "Baruch," but not opening with "Baruch."] Where the sages prescribe the lengthening of a benediction, it is not permitted to shorten it. Where they prescribe shortening, it is not permitted to lengthen. Where they prescribe closing [with "Baruch"], it is not permitted not to close. Where they prescribe not closing [as in the blessings over fruits and over mitzvoth], it is not permitted to close.