Synonym Boundary: "一つ", "もういちど", "片道", "いちいち", "相次いで"

When expressing "one" in Japanese, you must carefully distinguish between "一つ", "もういちど", "片道", "いちいち", "相次いで" 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」.
• 片道 (かたみち (katamichi) - Level: N4): Maps to "one way, single trip" and is used when Describes a journey to a destination without returning. Often used with きっぷ.
• 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..
• 相次いで (あいついで (aitsuide) - Level: N2): Maps to "one after another; in succession" and is used when Describes multiple events or incidents happening consecutively. Often used for significant or repeated occurrences..

Mixing these up can easily lead to unnatural translations. Refer to the bilingual context cards below to master the boundaries!