Plural Forms in Gettext: What They Are and When They Matter
Plural forms define how translations change depending on a number (for example “1 file” vs “2 files”).
In gettext-based localization, this information is stored in the Plural-Forms header of a PO file.
In modern Poedit versions, this is almost always handled for you automatically.
Why plural forms exist at all
Section titled “Why plural forms exist at all”English has only two grammatical forms for counted items: singular (1 file) and plural (2 files, 0 files, etc.). Many languages are more complex:
| Language | Examples |
|---|---|
| English | 1 file, 2 files |
| Czech | 1 soubor, 2 soubory, 3 soubory, 5 souborů |
| Slovenian | 1 datoteka, 2 datoteki, 3 datoteke, 5 datotek |
| Chinese | 1 个文件, 2 个文件, 5 个文件 (no grammatical plural) |
| Arabic | 0 ملف، 1 ملف، 2 ملفان، 3 ملفات، 11 ملفًا، 100 ملف |
Because languages vary so widely, gettext cannot hard-code plural rules. Instead, each translation specifies its own rule that tells gettext which plural form to use for a given number.
Important: plural forms only apply to counted messages
Section titled “Important: plural forms only apply to counted messages”Plural forms are used only for strings that include a numeric value, typically written in code using functions like ngettext().
Examples where plural forms matter:
- “%d file deleted”
- “You have %d messages”
Examples where they do not matter:
- Normal sentences without numbers
- UI labels like “Settings”, “Preferences”, “Open file”
This distinction is often misunderstood: plural rules do not affect ordinary translations, only messages that vary by number.
How gettext represents plural rules
Section titled “How gettext represents plural rules”Plural rules are stored in the PO file header as a Plural-Forms field. It is an expression that uses a C-like syntax and is evaluated whenever gettext chooses between plural variants:
nplurals=2; plural=(n == 1 ? 0 : 1);It has two parts:
- nplurals: how many plural forms the language has
- plural: an expression that selects the correct form based on
n(the number being evaluated)
The GNU gettext manual has a full description of the syntax.
Plural forms in Poedit today
Section titled “Plural forms in Poedit today”For most languages, you don’t need to think about plural forms at all. Poedit automatically knows the correct plural rules for each language and fills them in for you. In normal use, you should simply keep Use default rules for this language selected and move on.
When would you change this?
Section titled “When would you change this?”Almost never :)
You only need to set a custom plural expression if you know exactly why you’re doing it, for example:
- You’re working with a deliberately non-standard language variant
- You need to match a very specific legacy setup
If you’re unsure whether you should change it, the answer is no — the default is correct.