> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nt3.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Plural Forms & ICU

> Handle pluralization and complex message formatting with ICU syntax.

Different languages handle pluralization differently. English has two forms (one item / many items), but Russian has four, Arabic has six, and Chinese has none. Entri uses **ICU Message Format** to express these rules in a single string that works across all languages.

## ICU Message Format basics

ICU (International Components for Unicode) is the industry standard for complex message formatting. It uses a `{variable, type, ...options}` syntax embedded in your strings.

### Plurals

```
{count, plural, one {# item} other {# items}}
```

The `#` symbol is replaced with the value of `count`. The categories (`one`, `other`) follow CLDR plural rules for each language.

### Select

Use `select` to branch on a non-numeric variable, such as grammatical gender:

```
{gender, select, male {He liked this} female {She liked this} other {They liked this}}
```

### Ordinals

Use `selectordinal` for rank-style numbers:

```
{rank, selectordinal, one {#st place} two {#nd place} few {#rd place} other {#th place}}
```

## CLDR plural categories

The Unicode CLDR defines up to six plural categories per language:

| Category | Meaning                           |
| -------- | --------------------------------- |
| `zero`   | Exactly zero (or rule-based zero) |
| `one`    | Singular form                     |
| `two`    | Dual form (some languages only)   |
| `few`    | Small numbers (language-specific) |
| `many`   | Large numbers (language-specific) |
| `other`  | Default / catch-all (required)    |

Not all languages use all categories. The `other` category is always required as the fallback.

## Language examples

<Tabs>
  <Tab title="English">
    English uses only `one` and `other`.

    ```
    {count, plural,
      one   {# item found}
      other {# items found}
    }
    ```

    | count | Output          |
    | ----- | --------------- |
    | 0     | 0 items found   |
    | 1     | 1 item found    |
    | 2     | 2 items found   |
    | 100   | 100 items found |
  </Tab>

  <Tab title="French">
    French treats 0 and 1 as singular (`one`). Numbers 2 and above use `other`.

    ```
    {count, plural,
      one   {# élément trouvé}
      other {# éléments trouvés}
    }
    ```

    | count | Output             |
    | ----- | ------------------ |
    | 0     | 0 élément trouvé   |
    | 1     | 1 élément trouvé   |
    | 2     | 2 éléments trouvés |
  </Tab>

  <Tab title="Russian">
    Russian uses `one`, `few`, and `other`, with complex modulo rules.

    ```
    {count, plural,
      one   {# товар}
      few   {# товара}
      many  {# товаров}
      other {# товара}
    }
    ```

    | count       | Rule   | Output    |
    | ----------- | ------ | --------- |
    | 1, 21, 31   | `one`  | 1 товар   |
    | 2–4, 22–24  | `few`  | 2 товара  |
    | 5–20, 25–30 | `many` | 5 товаров |
  </Tab>

  <Tab title="Arabic">
    Arabic has the most plural forms: `zero`, `one`, `two`, `few`, `many`, and `other`.

    ```
    {count, plural,
      zero  {لا عناصر}
      one   {عنصر واحد}
      two   {عنصران}
      few   {# عناصر}
      many  {# عنصرًا}
      other {# عنصر}
    }
    ```
  </Tab>

  <Tab title="Japanese / Chinese">
    East Asian languages have no plural distinction — all numbers use `other`.

    ```
    {count, plural,
      other {# 件のアイテム}
    }
    ```

    In Japanese, Chinese, Korean, and similar languages, only the `other` category is needed.
  </Tab>
</Tabs>

## Nesting: plurals inside select

ICU rules can be nested to handle combinations:

```
{gender, select,
  male   {{count, plural, one {He found # result} other {He found # results}}}
  female {{count, plural, one {She found # result} other {She found # results}}}
  other  {{count, plural, one {They found # result} other {They found # results}}}
}
```

<Warning>
  Deeply nested ICU expressions can be difficult for translators to work with. Consider simplifying by splitting into separate keys when nesting goes beyond two levels.
</Warning>

## Entri editor support

The Entri translation editor provides dedicated input fields for each plural category required by the target language. Translators never need to write ICU syntax manually — the editor shows the appropriate form fields (e.g., `one`, `few`, `other` for Russian) and assembles the final ICU string automatically.

For AI translation, Entri recognizes ICU plural patterns and generates all required plural forms for the target language in a single operation.

## Using ICU in your codebase

ICU is supported by popular i18n libraries:

| Library                 | Platform      | ICU support              |
| ----------------------- | ------------- | ------------------------ |
| `react-i18next`         | React         | Via `i18next-icu` plugin |
| `FormatJS / react-intl` | React         | Native                   |
| `Lingui`                | React         | Native                   |
| `vue-i18n`              | Vue           | Native                   |
| `Angular i18n`          | Angular       | Native                   |
| `Flutter intl`          | Flutter (ARB) | Native                   |

## File format compatibility

ICU message format is stored as a plain string in your locale files. Any format that supports arbitrary string values — `json-flat`, `json-nested`, `yaml`, `po`, `arb` — can hold ICU strings without modification. The ICU parsing happens at runtime in your i18n library.

```json theme={null}
{
  "item_count": "{count, plural, one {# item} other {# items}}",
  "welcome": "Welcome, {name}!"
}
```