#grammar

English word inflection as an API. Pluralize or singularize any word — correctly handling the irregulars that trip up naive code (person ↔ people, cactus ↔ cacti, goose ↔ geese, analysis ↔ analyses, and uncountables like sheep and series). Get count-aware inflection ("1 item" vs "3 items", optionally with the number included), and check whether a given word is already singular or plural. Everything is computed locally, so it is instant and always available. Ideal for ORMs and code generators, REST resource naming, UI labels and notifications ("3 result(s)"), search and autocomplete, and any app that turns counts into correct grammar. For case styles and URL slugs, use the Text API.

api.oanor.com/inflector-api

Catch spelling mistakes in six languages — English, German, Spanish, French, Portuguese and Dutch — and get English style and grammar suggestions in one call. Spelling errors come with their position in the text and a ranked list of corrections; style suggestions flag repeated words, weasel words, passive voice, wordiness, clichés and more. A combined check returns spelling and style together (sorted by position), a spelling-only endpoint covers all six languages, a single-word endpoint returns corrections for one word, and a languages endpoint lists what is supported. Every endpoint takes text via the query string or the request body and returns lean JSON. Pure server-side computation (Hunspell dictionaries + write-good, no third-party upstream, no LLM cost), so responses are instant and always available. Ideal for editors and CMSs, form and comment validation, chat and email tools, and writing assistants.

api.oanor.com/grammar-api