その選手は日本のみならず外国でも大人気です。
- That athlete is very popular not only in Japan but also overseas.

その選手は日本のみならず外国でも大人気です。 meaning: That player is very popular not only in Japan but also in foreign countries.

⚫︎ The sentence structure follows the subject-topic-comment pattern, typical of Japanese. ⚫︎ その選手 is the subject, "that player." ⚫︎ The topic marker は (wa) indicates the topic being discussed. ⚫︎ The comment is 大人気です, which is the main point being made about the subject. ⚫︎ Particles are crucial in Japanese for indicating relationships between words: ⚫︎ の (no) - possessive, indicates "of" or "belonging to". This particle doesn't appear in this specific sentence, but is frequently used. ⚫︎ に (ni) - indicates location ("in" or "at"), time, purpose, or direction. In this sentence, it's used with のみならず to indicate the scope ("in Japan"). ⚫︎ も (mo) - "also" or "too." Indicates addition. ⚫︎ で (de) - indicates the location of an action or state ("in" or "at").

⚫︎ のみならず is a fixed expression meaning "not only...but also..." or "as well as." ⚫︎ It is used to add extra information to the first part. ⚫︎ The basic structure is: Noun + のみならず + (related phrase). ⚫︎ In this sentence, it connects "Japan" and "foreign countries." ⚫︎ 日本のみならず - "not only in Japan" ⚫︎ 外国でも - "also in foreign countries" ⚫︎ This phrase is often used to emphasize the breadth or scope of something.

⚫︎ 大人気 (daininki) is an adjectival noun, meaning "very popular" or "extremely popular." ⚫︎ Adjectival nouns are modified by the particle な before nouns. However, when they act as the predicate of a sentence, the な is dropped. ⚫︎ The copula です (desu) is a polite form of "to be" or "is/are/am." It adds politeness to the sentence. ⚫︎ The stem of です is で. The polite past tense would be でした (deshita - was/were). ⚫︎ 大人気です is the complete predicate, meaning "is very popular."

⚫︎ The particle で is used to indicate the location of an action or state. ⚫︎ In this context, it indicates the location where the player is popular. ⚫︎ 外国で indicates "in foreign countries." ⚫︎ While に could also be used to indicate location in specific scenarios, で is more appropriate here when describing the state of being popular.

⚫︎ The sentence exemplifies several key N2-level grammar points: ⚫︎ Sentence structure and particle usage. ⚫︎ Fixed expressions (like のみならず) that are commonly used to create complex and nuanced sentences. ⚫︎ Understanding and use of adjectival nouns and the copula です to form predicates. ⚫︎ This sentence demonstrates the ability to express complex ideas using concise and grammatically correct Japanese.