Vocabulary: Meaning, Collocation, and Confusable Pairs
What N3 vocabulary tests
The N3 vocabulary section asks you to choose the word that fits a short sentence. It tests four overlapping areas: kanji readings and compounds (人口, 出身, 経験), verb and adjective meanings including transitive/intransitive pairs (開く/開ける, 直る/直す), katakana loanwords (トラブル, スケジュール), and fixed collocations with particles (熱が出る, 約束を守る). Roughly 3,750 words are in scope, but questions recycle a core set of high-frequency items.
Traps
Similar-looking kanji are a common trap: 相談/観察, 関心/感心, 質問/訪問. Another is synonym choice: すぐに/急に/突然 all translate near "suddenly" but differ in nuance and collocation. Transitive/intransitive pairs catch candidates because the particle changes with the verb: ドアが開く versus ドアを開ける. Katakana words often have a narrower meaning than the English source (マンション is a condominium, not a mansion). Adverbs and onomatopoeia (しっかり, そっと, ぐっすり) are tested by context, not by translation.
Worked rule
When you meet a verb in a sentence, identify its particle pattern first. For 直す (to fix or repair), the object is a thing: 時計を直す. For 治す, the object is an illness or a person's condition: 病気を治す. If the sentence contains 病気, choose 治す; if it contains 壊れた時計, choose 直す. Learn each new verb with one particle frame and one typical object, and review in pairs rather than as isolated translations.