大きい
おおきい
ookii
= big; large; great
大きい (ookii) is one of the first adjectives Japanese learners encounter — and one of the trickiest to fully master. While it straightforwardly means “big” or “large,” it stretches far beyond physical size to describe volume, magnitude, and even emotional weight.
大きい is an i-adjective meaning “big,” “large,” or “great.” It describes physical dimensions (a big box, a large room) but also abstract scale: a loud voice (大きい声, ookii koe), a major mistake (大きい失敗, ookii shippai), or a significant dream. As a true i-adjective, it conjugates fully: 大きくない (not big), 大きかった (was big), 大きくなる (to become big/grow up). This sets it apart from 大きな (ookii-na), a pre-noun modifier that looks similar but is actually a rentaishi (連体詞) — a special uninflectable word that can only directly precede nouns (大きな夢, a big dream) and cannot serve as a predicate. You cannot say ✗「夢は大きなだ」but you can say ○「夢は大きい」. In casual speech both forms appear before nouns (大きい犬 / 大きな犬 both mean “a big dog”), but only 大きい can end a sentence or take tense endings.
The most common mistake is mixing up 大きい and 大きな. Remember: 大きい is a real adjective that conjugates; 大きな is a fixed modifier that never changes form and never ends a sentence. Test yourself — if you can replace it with 大きくない to negate it, use 大きい; if the word is locked in place before a noun and you want a slightly more literary or emphatic feel, 大きな works. A second trap is the compound reading: seeing 大 and assuming it always reads おお. In words like 大切 (たいせつ) or 大学 (だいがく), the reading shifts to たい or だい. Finally, 大きい covers loudness (大きい音, loud sound) and importance (大きい問題, a major issue) — not just physical size — so resist the urge to reach for another adjective when describing anything of significant scale.
大 is one of the most ancient and visually intuitive kanji. It depicts a person (人) with arms stretched wide open, conveying the idea of “as large as a human can reach.” With the addition of the い suffix marking it as an i-adjective, 大きい literally evokes that image of arms spread wide. The same character appears in many compounds but often changes reading: 大人 (おとな, adult), 大阪 (おおさか, Osaka), 大学 (だいがく, university), 大切 (たいせつ, important). Learners should note that 大 reads おお in native Japanese words, but だい or たい in Sino-Japanese (on’yomi) compounds.
Everyday use
この荷物は大きいから、一人では運べない。
Kono nimotsu wa ookii kara, hitori de wa hakobenai.
This luggage is big, so I can’t carry it alone.
Casual / Social Media
え、そんな大きい声で話さないで！周りに聞こえるよ。
E, sonna ookii koe de hanasanaide! Mawari ni kikoeru yo.
Hey, don’t talk in such a loud voice! People around us can hear you.
Formal / Cultural context
今回の不祥事は会社にとって大きい損失となった。
Konkai no fushōji wa kaisha ni totte ookii sonshitsu to natta.
This scandal resulted in a major loss for the company.
In Japanese culture, restraint and modesty are often prized, which makes 大きい particularly interesting when applied to abstract concepts. Saying someone has 大きい夢 (a big dream) or 大きい志 (great ambition) carries genuine admiration — dreaming boldly is encouraged even in a society that values humility in everyday behavior. Children are often praised with 大きくなったね (You’ve grown so big!) as a marker of growth and maturity, making the word deeply tied to the passage of time and personal development.
The phrase 大きなお世話 (ookii-na osewa) — literally “big meddling” — is a pointed way to tell someone to mind their own business. It uses 大きな rather than 大きい, illustrating how the 大きな form often appears in set phrases and idioms that carry cultural weight. Similarly, 大きい顔をする (to act big / to be full of oneself) uses physical size as a metaphor for arrogance, a concept that resonates in Japanese social contexts where standing out inappropriately is frowned upon.