one
- 01 A1 Beginner
num.the number 1, which comes before 2.
num.the first positive integer in the set of natural numbers; the cardinal number represented by the Arabic numeral 1.
Simple“I have one brother and two sisters.”
In context“The mathematician explained that one is the identity element for multiplication in any standard ring structure.”
- 02 B2 Upper Intermediate
pron.any person or people in general.
pron.an impersonal pronoun used to refer to people in general, including the speaker.
Simple“One should always be polite to their neighbors.”
In context“One must consider the ethical implications before embarking on such a radical course of action.”
UsageIn modern English, 'you' is much more common than 'one' for this meaning.
- 03 B1 Intermediate
n.the perfect person for a romantic relationship.
n.a person regarded as a uniquely suitable romantic partner.
Simple“After three years of dating, he finally realized she was the one.”
In context“Despite several failed relationships, she remained optimistic that she would eventually find the one.”
Synonymssoulmate - 04 A2 Elementary
adj.being the only person or thing of a particular type.
adj.functioning as a determiner or adjective to indicate a single or sole entity.
Simple“He is the one person I can truly trust with a secret.”
In context“The CEO remained the one individual capable of uniting the board during the hostile takeover bid.”
- 05 B1 Intermediate
adj.used to talk about a specific time in the past or future.
adj.referring to a particular but unspecified time or occasion.
Simple“One day, I hope to travel all around the world.”
In context“One evening, quite unexpectedly, a letter arrived that would change the course of his professional life forever.”
Synonyms
Usage one day · one person · one point
PIE word *h₁óynos From Middle English oon, on, oan, an, from Old English ān (“one”), from Proto-West Germanic ain, from Proto-Germanic ainaz (“one”), from Proto-Indo-European *h₁óynos (“single, one”). Doublet of an. Cognate with Scots ae, ane, wan, yin (“one”); North Frisian ån (“one”); Saterland Frisian aan (“one”); West Frisian ien (“one”); Dutch een, één (“one”); German Low German een; German ein, eins (“one”); Danish en (“one”); Swedish en (“one”); Norwegian Nynorsk ein (“one”), Icelandic einn (“one”); Latin ūnus (“one”) (Old Latin oinos); Russian оди́н (odín), Spanish uno. Doublet of a, an, and Uno. False cognate of Malayalam ഒന്ന് (onnŭ), Tamil ஒன்னு (oṉṉu), ஒண்ணு (oṇṇu), ஒன்று (oṉṟu). The use as an indefinite personal pronoun may have been influenced by unrelated French on, although the Germanic languages widely use cognates for the same sense (usually in non-subject function, but also in subject function, e.g. Luxembourgish een). Verb form from Middle English onen.
Analogous to several senses of Hokkien 個/个 (ê) and Mandarin 的 (de, declarative particle, nominalizer, etc.). This semantic loan might have stemmed from the apparent similarity between one as a prop-word and 的 (de) or 個 /个 (ê) as a nominalizer (e.g. 青色的 (“the green one”)). Compare Cantonese 嘅 (ge³).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Mandarin lacks a generic third-person indefinite pronoun like the formal 'one' and uses 人 (rén) or 大家 (dàjiā) instead. Consequently, learners often use 'people' or 'everyone' in academic contexts where 'one' is more appropriate for maintaining an impersonal tone.
The Mandarin measure word 一个人 (yí gè rén) is often translated word-for-word, leading to the redundant use of 'one person' in sentences like 'I saw one person there' when English typically prefers 'someone' or 'a person'.
Japanese phonology lacks the /w/ sound before vowels other than /a/; speakers often substitute a /u/ vowel or the glottal stop /ʔ/, realizing 'one' /wʌn/ as /wan/ or /u-an/.
Japanese utilizes specific numerical counters (助数詞 josūshi) based on the object's shape or type; learners often default to 'one' followed by a noun instead of the required English countability structures, or omit the indefinite pronoun usage of 'one' entirely because Japanese lacks a direct pronominal equivalent.
The Japanese phrase 'one-pattern' ワンパターン (wan-patān) refers to being repetitive or predictable, leading to the incorrect use of 'one pattern' in English to describe a boring person or situation.