One is a personal pronoun in the English language. It is a gender neutral, third person singular pronoun, commonly used in English prose. It is equivalent to the French pronoun on, or the German man. The English language is a West Germanic language that originates in England. ... Personal pronouns in French: The French possessive pronouns (mon, ma, mes, ton, ta, tes, son, sa, ses, notre, notre, nos, votre, votre, vos, leur, leur, leurs) are technically adjectives because they decline into masculine, feminine and plural forms and further agree with their heads (not their antecedents). ...

It may be used in the nominative or accusative cases, but never in the dative case. It occurs most commonly in sentences in the present simple tense or the conditional tense. Examples of its use: The nominative case is a grammatical case for a noun, which generally marks the subject of a verb, as opposed to its object or other verb arguments. ... The accusative case of a noun is the grammatical case used to mark the direct object of a verb. ... The dative case is a grammatical case generally used to indicate the noun to whom something is given. ... The present tense is the tense (form of a verb) that is often used to express: Action at the present time A state of being A habitual action An occurrence in the near future An action that occurred in the past and continues up to the present There are two... The conditional tense (sometimes described as the conditional mood) is a verb form in many languages, in which a verb root is modified to form verb tenses, moods, or aspects expressing degrees of certainty or uncertainty and hypothesis about past, present, or future. ...

One cannot help but grow older.

If one were to fail, that would be unfortunate.

Some consider its use to be overly formal, and actively avoid it. However, in doing so, they encounter problems, which can only be resolved by awkward phrasings or a significant drop in formality. In particular, phrasing a sentence in a gender neutral way can otherwise be achieved only by use of the passive voice, which makes sentences hard to understand, or by resorting to the singular they or second person ('you'), or to pseudo-English such as sie and hir. In grammar, voice is the relationship between the action or state expressed by a verb, and its arguments (subject, object, etc. ... Singular they, sometimes called epicene they, is the usage in the English language of the gender-neutral third-person plural pronoun they and its inflected forms — they, them, their, theirs, themselves (or themself) — to refer to a single person, often of indeterminate sex, as for example in: Have you ever... Sie and hir are inflected forms of a proposed gender-neutral third person singular personal pronoun for the English language (see gender-neutral pronouns). ...