🦅 Project Eagle
Quintuple VS

Synonym Boundary: "一つ", "もういちど", "いちいち", "逐一", "一因"

All represent the core concept "one", but require precise selection.

Japanese Option A

一つ

ひとつ (hitotsu)
N5 / CEFR
Japanese Option B

もういちど

もういちど (mou ichido)
N5 / CEFR
Japanese Option C

いちいち

いちいち (ichiichi)
N2 / CEFR
Japanese Option D

逐一

ちくいち (chikuichi)
N2 / CEFR
Japanese Option E

一因

いちいん (ichiin)
N2 / CEFR

Quintuple VS Nuance Contrast & Social Differences

When expressing "one" in Japanese, you must carefully distinguish between "一つ", "もういちど", "いちいち", "逐一", "一因" based on context.
  • 一つ (ひとつ (hitotsu) - Level: N5): Maps to "one (general counter for objects)" and is used when Used for counting general items, especially small, individual objects, when a specific counter is not needed or known..
  • もういちど (もういちど (mou ichido) - Level: N5): Maps to "One more time; Again" and is used when Used to request repetition or another attempt. Often combined with 「お願いします」.
  • いちいち (いちいち (ichiichi) - Level: N2): Maps to "one by one; in detail; item by item; minutely; every single time (often implies annoyance or unnecessary thoroughness)" and is used when Implies going through things individually or paying attention to every small detail. Can convey a sense of annoyance when someone is being excessively meticulous or complaining about every little thing..
  • 逐一 (ちくいち (chikuichi) - Level: N2): Maps to "one by one, in detail, item by item" and is used when To do or report things individually, sequentially, and in full detail. It emphasizes meticulousness and thoroughness. Often used with verbs like 報告する.
  • 一因 (いちいん (ichiin) - Level: N2): Maps to "one cause; a contributing factor" and is used when Used to indicate one of several causes or factors contributing to a situation, often a negative one..
Mixing these up can easily lead to unnatural translations. Refer to the bilingual context cards below to master the boundaries!
Context for "一つ"
りんごを一つください。
Please give me one apple.
Context for "もういちど"
もう一度言ってください。
Please say it one more time.
Context for "いちいち"
彼は部下のやることに、いちいち口を出す。
He interferes with every single thing his subordinates do.
Context for "逐一"
彼は出張の進捗状況を逐一報告してくれた。
He reported the progress of his business trip in detail, item by item.
Context for "一因"
彼の失敗は準備不足が一因だ。
His failure was partly due to insufficient preparation.

Synonym Mastery Challenge

Which Japanese word perfectly fits this blank space?

Fill in the blank: "りんごを ___ ください。" (Meaning: "Please give me one apple.")
🎉 Correct Answer!

Remember: "一つ" is correct here because it represents "one (general counter for objects)" in the context: "Please give me one apple.".

💡 Practice with AI! Live

Don't just read. Practice speaking this grammar with our interactive AI coach for free!

Try AI Speaking 👉