Question

조용히 있겠다고 약속할게요 Indirect quotations are used when reporting someone's speech without adding the original phrase into the sentence. This type of quotations is formed by adding -고 to the plain style ending. The general grammatical rule for making indirect quotes can be described as:...[stem] + [plain ending] + 고 ... [quoting verb]The plain speech style is a rather complex category providing different endings for statements, questions, imperative and proposative phrases. These endings also vary for verbs and adjectives. Mastering the indirect quotation implies learning rules for a set of grammatical cases.The plain style statement ending -(은/는)다 is used when forming indirect quotations of statements. The -다고 principle attaches to adjective stems; -ㄴ다고 follows verb stems ending in a vowel; and, finally, -는다고 attaches after verb stems ending in a consonant. In cases when the stem comes with the past -았/었- or the future -겠- tense particle the -다고 principle is used. After the honorific -(으)시- comes -ㄴ다고, if it's a verb stem, or -다고 in case of an adjective.

Accepted Answer

I promise I will be quiet

Front	조용히 있겠다고 약속할게요
Back	I promise I will be quiet
Notes	Indirect quotations are used when reporting someone's speech without adding the original phrase into the sentence. This type of quotations is formed by adding -고 to the plain style ending. The general grammatical rule for making indirect quotes can be described as: ...[stem] + [plain ending] + 고 ... [quoting verb] The plain speech style is a rather complex category providing different endings for statements, questions, imperative and proposative phrases. These endings also vary for verbs and adjectives. Mastering the indirect quotation implies learning rules for a set of grammatical cases. The plain style statement ending -(은/는)다 is used when forming indirect quotations of statements. The -다고 principle attaches to adjective stems; -ㄴ다고 follows verb stems ending in a vowel; and, finally, -는다고 attaches after verb stems ending in a consonant. In cases when the stem comes with the past -았/었- or the future -겠- tense particle the -다고 principle is used. After the honorific -(으)시- comes -ㄴ다고, if it's a verb stem, or -다고 in case of an adjective.

Indirect Quotations Plain Style Ending 다고 Verb Speech