大きいこえでうたってはいけない。
- 큰 소리로 노래하면 안 된다.

大きいこえでうたってはいけない。 meaning: 큰 소리로 노래를 불러서는 안 된다.

Explanation of the first grammar point ⚫︎ Sentence Structure: The sentence follows the typical Japanese Subject-Object-Verb (SOV) structure, although the subject is often omitted if it's understood from the context. * The sentence can be divided into 大きいこえで + うたって + はいけない。 ⚫︎ こえ (voice) + 大きい (big): This creates the adverbial phrase 大きいこえで, meaning "in a loud voice" or "loudly". * 大きい is an い-adjective, modifying the noun こえ. * で is a particle indicating the means or manner. ⚫︎ うたって + はいけない: This part forms the verb phrase. * うたって is the て-form of the verb うたう (to sing). * はいけない is a fixed expression that means "must not," "should not," or "it is not allowed to." * It is a negative auxiliary verb. ⚫︎ Example: 小さいこえで話してください。 (Please speak in a low voice.)

Explanation of the second grammar point ⚫︎ The particle で is used to indicate the place where an action takes place, the means or method used to do something, or the reason/cause of something. ⚫︎ In this sentence, で indicates the "means" or "manner" (using a loud voice). * 大きいこえ (a loud voice) - means/manner * うたう (to sing) - action ⚫︎ Examples: * バスで学校に行きます。 (I go to school by bus.) - means of transportation * 日本語で話してください。 (Please speak in Japanese.) - means of communication

Explanation of the third grammar point ⚫︎ The て-form of a verb is very important in Japanese grammar. It's used to connect verbs, show the order of actions, and in fixed expressions. ⚫︎ In this sentence, うたう (to sing) is conjugated to its て-form, うたって. ⚫︎ How to form the て-form (for the verbs in this sentence): * うたう (to sing): Change the ending "う" to "って" -> うたって. * This applies to other verbs in the "う" column: 買う(to buy) -> 買って, 会う(to meet) -> 会って ⚫︎ Example: * 食べて、飲みます。 (I eat and drink.) - shows the sequence of actions. * 本を読んでください。 (Please read the book.) - used with the command form, 〜てください。

Explanation of the fourth grammar point ⚫︎ 〜てはいけない is a fixed expression that expresses prohibition or something that is not allowed. It means "must not" or "should not." ⚫︎ It is formed by combining the て-form of a verb with the auxiliary verb はいけない. ⚫︎ The て-form and はいけない always go together. ⚫︎ Examples: * ここでたばこを吸ってはいけません。 (You must not smoke here.) * 遅刻してはいけません。 (You must not be late.)

Explanation of the fifth grammar point ⚫︎ 大きい (ookii) is an い-adjective, which means "big" or "loud." ⚫︎ い-adjectives directly modify nouns. For example, 大きいこえ (big voice / loud voice). ⚫︎ The most important thing to remember is the adjective's role in the sentence. ⚫︎ Examples: * 小さい犬 (a small dog) * 新しい車 (a new car) * 高い山 (a tall mountain)