日本語を勉強する上で復習はとても大切です。
- In studying Japanese, reviewing is very important.

日本語を勉強する上で復習はとても大切です。 meaning: Review is very important when studying Japanese.

⚫︎ The basic sentence structure in Japanese is Subject-Object-Verb (SOV). ⚫︎ In this sentence, 復習(fukushuu - review) is the subject. ⚫︎ The topic marker は(wa) follows 復習, indicating the topic of the sentence. It highlights what the sentence is *about*. ⚫︎ The subject is often omitted if it's clear from the context. ⚫︎ The sentence's core is 復習は大切です(fukushuu wa taisetsu desu - Review is important).

⚫︎ 上で(ue de) is a fixed expression indicating a condition or a circumstance. It means "when it comes to," "in terms of," or "upon" and is often used to describe a context. ⚫︎ It is formed by attaching 上(ue - on/above/upon) to a verb in its dictionary form or a noun + の (no). ⚫︎ In this sentence, 勉強する(benkyou suru - to study) is in its dictionary form and becomes 勉強する上で(benkyou suru ue de - when studying/ in the process of studying). ⚫︎ It sets the context for the rest of the sentence. ⚫︎ Other examples: ⚫︎ 料理を作る上で、味見が大切です(ryouri o tsukuru ue de, aji mi ga taisetsu desu - Tasting is important when making food.) ⚫︎ 健康のため上で、運動が重要です(kenkou no tame ue de, undou ga juyou desu - Exercise is important for the sake of health.)

⚫︎ 大切(taisetsu) is an adjectival noun (also called a "na-adjective"). ⚫︎ Adjectival nouns describe nouns and, unlike i-adjectives, need な(na) before the noun they modify. However, in this sentence, there's no noun being modified directly. ⚫︎ Adjectival nouns can also be used as the predicate (the part that says something about the subject). ⚫︎ When an adjectival noun is the predicate, it's followed by です(desu), which adds politeness and indicates the present tense. ⚫︎ です(desu) is a polite form of the copula "to be". It indicates that the subject (review) *is* (important). ⚫︎ Other conjugations and uses: ⚫︎ 大切でした(taisetsu deshita - was important - past tense) ⚫︎ 大切ではありません(taisetsu dewa arimasen - is not important - negative present) ⚫︎ 大切ではありませんでした(taisetsu dewa arimasen deshita - was not important - negative past)

⚫︎ とても(totemo) is an adverb. ⚫︎ Adverbs modify verbs, adjectives, and other adverbs, providing more information about them. ⚫︎ とても(totemo) specifically means "very" or "really". ⚫︎ In this sentence, it modifies the adjectival noun 大切(taisetsu), strengthening the meaning of "important." ⚫︎ It emphasizes how important the review is.

⚫︎ Particle を(o): Marks the direct object of a verb. It answers the question "what?" or "whom?". ⚫︎ In this sentence, 日本語を勉強する(nihongo o benkyou suru - to study Japanese) the particle を(o) marks the object of the verb 勉強する(benkyou suru - to study). Therefore, 日本語(nihongo - Japanese) is the object. ⚫︎ Particle は(wa): Marks the topic of the sentence. It indicates what the sentence is about. ⚫︎ In this sentence, 復習(fukushuu - review) is the topic, and the whole sentence gives information about it. ⚫︎ These particles are essential for understanding the relationships between words in a Japanese sentence.