8.2 Adjectives & Adverbs

Describing the World: N5 Adjectives

Adjectives let you say something is big, cheap, quiet, or convenient — and the JLPT N5 tests roughly 60-70 of them. Japanese has two adjective classes, and telling them apart is the first skill the exam checks. い-adjectives (i-adjectives) end in the hiragana い and change their own ending: 大きい (おおきい, ōkii, big) → negative 大きくない → past 大きかった. な-adjectives (na-adjectives) look and behave more like nouns; they need the particle な when placed directly before a noun: 静か (しずか, shizuka, quiet) → 静かな部屋 (a quiet room).

い-adjective antonym pairs

The fastest way to double your adjective vocabulary is to learn opposites in pairs. Each pair below is a single sentence you can memorise.

Example sentences: 「この かばんは 大きいです」— This bag is big. 「あの えいがは おもしろかったです」— That movie was interesting (past 〜かった). 「へやは 新しくないです」— The room is not new (negative 〜くない, drop い → くない).

The one irregular you must know is いい (good). It is the casual form of よい, and it inflects from the よ- stem: negative よくない, past よかった, te-form よくて. Writing いくない or いかった is a classic wrong answer the exam plants as a distractor. So 「てんきが よかったです」= The weather was good, never いかったです.

な-adjective antonym pairs

な-adjectives drop the な before です but restore it before a noun. Their negative uses じゃありません / ではありません (or casual じゃない), not くない.

Watch two traps here. きれい ends in い but is a な-adjective (きれいな へや, a clean room; negative きれいじゃない) — the い is part of the root, not an inflecting ending. Likewise きらい (disliked) and ゆうめい (famous) end in い but are な-adjectives. Second, the antonym of a な-adjective is often an い-adjective: the opposite of 静か (quiet, な) is にぎやか (lively, な), but the opposite of ひま (free, な) is いそがしい (busy, い). Learn each word's class individually.

Example sentences: 「この まちは 静かです」— This town is quiet. 「これは 便利な アプリです」— This is a convenient app (な before noun). 「日本語が 上手じゃありません」— I am not good at Japanese (な-adjective negative).

Frequency and degree adverbs

Adverbs modify verbs and adjectives to show how much or how often. The N5 tests their polarity — whether they pair with an affirmative or a negative.

• とても (totemo, very): affirmative — 「とても おいしいです」(very delicious).
• よく (yoku, often / well): affirmative — 「よく えいがを 見ます」(I often watch movies).
• すこし (sukoshi, a little): 「すこし つかれました」(a little tired). More casual: ちょっと.
• たいてい (taitei, usually / mostly): 「たいてい うちで 食べます」(I usually eat at home).
• あまり (amari, not very): requires a negative — 「あまり 高くないです」(not very expensive). Using あまり with an affirmative is wrong.
• ぜんぜん (zenzen, not at all): requires a negative — 「ぜんぜん わかりません」(I don't understand at all).
• もっと (motto, more), たくさん (takusan, a lot), いつも (itsumo, always), ときどき (tokidoki, sometimes).

A classic exam item shows a blank before an adjective and asks you to choose the adverb. If the sentence ends in a negative (〜ません / 〜くない), the answer is almost always あまり or ぜんぜん; if it ends affirmatively and expresses strong degree, the answer is とても. In a real N5 question, 「きのう えいがを みて、（　）たのしかったです」the correct fill is とても — the sentence is affirmative and past-affirmative たのしかった, so とても (very) fits and あまり/ぜんぜん (which need a negative) do not.

How the four adjective forms behave

Because the exam tests inflection as well as meaning, it helps to see all four basic forms side by side for each class. An い-adjective keeps its stem and swaps the final い: present affirmative 高い (expensive), present negative 高くない (not expensive), past affirmative 高かった (was expensive), past negative 高くなかった (was not expensive). Attach です to any of these to make them polite: 高いです, 高くないです, 高かったです, 高くなかったです. A な-adjective does not inflect its own ending at all; instead you change the copula that follows it: present 便利です (is convenient), negative 便利じゃありません (is not convenient), past 便利でした (was convenient), past negative 便利じゃありませんでした (was not convenient). The takeaway is mechanical but reliable — い-adjectives carry their own tense, な-adjectives borrow tense from です/でした. When two adjectives are joined, い-adjectives use the て-form 〜くて (安くて おいしい, cheap and delicious) while な-adjectives use で (しずかで きれい, quiet and clean).

More high-yield adjectives and usage notes

Round out your bank with adjectives that appear constantly in N5 reading passages: あかるい (bright) / くらい (dark), あつい (hot to touch) / つめたい (cold to touch — distinct from さむい, which is for weather), むずかしい (difficult) / やさしい (easy or kind), おいしい (delicious) / まずい (bad-tasting), いそがしい (busy), たのしい (fun), うれしい (glad), かなしい (sad), ちかい (near) / とおい (far), ひろい (spacious) / せまい (cramped). Among な-adjectives, add たいせつ (important), だいじょうぶ (all right), いろいろ (various), and かんたん (simple). Two temperature pairs trap learners: use あつい／さむい for the weather or air but あつい／つめたい for objects you touch such as coffee or water. Similarly, やさしい means both easy and kind, so the reading context decides which gloss the answer wants.

One more usage point the exam checks is degree adverbs with quantity. たくさん (a lot) and すこし (a little) modify amounts of things, often with a verb: 「水を たくさん のみます」(I drink a lot of water). とても modifies the strength of a quality (とても たかい). Do not swap them — 「とても のみます」is unnatural. And remember the negative-polarity duo one final time: whenever the predicate ends in a negative such as 〜くないです or 〜ません, scan the answer choices for あまり or ぜんぜん first, because the test writers almost always hide the correct adverb there. This single polarity rule resolves a surprising share of the fill-in-the-blank vocabulary items on the real N5. As a study habit, record every new adjective with its class label (い or な) and one antonym, because the exam tests opposites as often as it tests the words themselves, and a word paired with its opposite is roughly twice as easy to recall under time pressure. Finally, note that a small set of words look like adjectives but are actually nouns or adverbs — for example おなじ (same) attaches directly to a noun without な, so 「おなじ かばん」means the same bag; treat it as a fixed exception rather than a regular な-adjective.