diff --git a/README.md b/README.md
index 3e1e3ee..d5445f1 100644
--- a/README.md
+++ b/README.md
@@ -828,7 +828,29 @@ Whenever an exception is caught by `Application::handle()`, it will show a beaut
 
 ![Exception Preview](https://user-images.githubusercontent.com/2908547/44401057-8b350880-a577-11e8-8ca6-20508d593d98.png "Exception trace")
 
-### Autocompletion
+## I18n Support
+
+**adhocore/cli** also supports internationalisation. This is particularly useful if you are not very comfortable with English or if you are creating a framework or CLI application that could be used by people from a variety of backgrounds.
+
+By default, all the texts generated by our system are in English. But you can easily modify them by defining your translations as follows
+
+```php
+\Ahc\Application::addLocale('fr', [
+    'Only last argument can be variadic' => 'Seul le dernier argument peut être variadique',
+], true);
+```
+
+You can also change the default English text to make the description more explicit if you wish.
+
+```php
+\Ahc\Application::addLocale('en', [
+    'Show help' => 'Shows helpful information about a command',
+]);
+```
+
+vous pouvez trouver toutes les clés de traduction supportées par le paquet dans cette gist : https://gist.github.com/dimtrovich/1597c16d5c74334e68eef15a4e7ba3fd
+
+## Autocompletion
 
 Any console applications that are built on top of **adhocore/cli** can entertain autocomplete of commands and options in zsh shell with oh-my-zsh.
 
diff --git a/composer.json b/composer.json
index b942bb9..e91b0fc 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,10 @@
     "autoload": {
         "psr-4": {
             "Ahc\\Cli\\": "src/"
-        }
+        },
+        "files": [
+            "src/functions.php"
+        ]
     },
     "autoload-dev": {
         "psr-4": {
diff --git a/src/Application.php b/src/Application.php
index 187089c..27a70a4 100644
--- a/src/Application.php
+++ b/src/Application.php
@@ -12,6 +12,7 @@
 namespace Ahc\Cli;
 
 use Ahc\Cli\Exception\InvalidArgumentException;
+use Ahc\Cli\Helper\InflectsString;
 use Ahc\Cli\Helper\OutputHelper;
 use Ahc\Cli\Input\Command;
 use Ahc\Cli\IO\Interactor;
@@ -28,7 +29,6 @@
 use function is_array;
 use function is_int;
 use function method_exists;
-use function sprintf;
 
 /**
  * A cli application.
@@ -40,6 +40,23 @@
  */
 class Application
 {
+    /**
+     * Locale of CLI.
+     */
+    public static $locale = 'en';
+
+    /**
+     * list of translations for each supported locale
+     *
+     * @var array<string, array>
+     *
+     * @example
+     * ```php
+     *  ['locale' => ['key1' => 'value1', 'key2' => 'value2']]
+     * ```
+     */
+    public static $locales = [];
+
     /** @var Command[] */
     protected array $commands = [];
 
@@ -130,6 +147,15 @@ public function logo(?string $logo = null)
         return $this;
     }
 
+    public static function addLocale(string $locale, array $texts, bool $default = false)
+    {
+        if ($default) {
+            self::$locale = $locale;
+        }
+
+        self::$locales[$locale] = $texts;
+    }
+
     /**
      * Add a command by its name desc alias etc and return command.
      */
@@ -161,7 +187,7 @@ public function add(Command $command, string $alias = '', bool $default = false)
             $this->aliases[$alias] ??
             null
         ) {
-            throw new InvalidArgumentException(sprintf('Command "%s" already added', $name));
+            throw new InvalidArgumentException(t('Command "%s" already added', [$name]));
         }
 
         if ($alias) {
@@ -190,7 +216,7 @@ public function add(Command $command, string $alias = '', bool $default = false)
     public function defaultCommand(string $commandName): self
     {
         if (!isset($this->commands[$commandName])) {
-            throw new InvalidArgumentException(sprintf('Command "%s" does not exist', $commandName));
+            throw new InvalidArgumentException(t('Command "%s" does not exist', [$commandName]));
         }
 
         $this->default = $commandName;
@@ -386,8 +412,8 @@ public function showHelp(): mixed
     public function showDefaultHelp(): mixed
     {
         $writer = $this->io()->writer();
-        $header = "{$this->name}, version {$this->version}";
-        $footer = 'Run `<command> --help` for specific help';
+        $header = "{$this->name}, " . t('version') . " {$this->version}";
+        $footer = t('Run `<command> --help` for specific help');
 
         if ($this->logo) {
             $writer->logo($this->logo, true);
diff --git a/src/Helper/OutputHelper.php b/src/Helper/OutputHelper.php
index 5f54200..00e2af7 100644
--- a/src/Helper/OutputHelper.php
+++ b/src/Helper/OutputHelper.php
@@ -20,6 +20,7 @@
 use Ahc\Cli\Output\Writer;
 use Throwable;
 
+use function Ahc\Cli\t;
 use function array_map;
 use function array_shift;
 use function asort;
@@ -58,6 +59,8 @@
  */
 class OutputHelper
 {
+    use InflectsString;
+
     protected Writer $writer;
 
     /** @var int Max width of command name */
@@ -77,7 +80,7 @@ public function printTrace(Throwable $e): void
 
         $this->writer->colors(
             "{$eClass} <red>{$e->getMessage()}</end><eol/>" .
-            "(thrown in <yellow>{$e->getFile()}</end><white>:{$e->getLine()})</end>"
+            '(' . t('thrown in') . " <yellow>{$e->getFile()}</end><white>:{$e->getLine()})</end>"
         );
 
         // @codeCoverageIgnoreStart
@@ -87,7 +90,7 @@ public function printTrace(Throwable $e): void
         }
         // @codeCoverageIgnoreEnd
 
-        $traceStr = '<eol/><eol/><bold>Stack Trace:</end><eol/><eol/>';
+        $traceStr = '<eol/><eol/><bold>' . t('Stack Trace') . ':</end><eol/><eol/>';
 
         foreach ($e->getTrace() as $i => $trace) {
             $trace += ['class' => '', 'type' => '', 'function' => '', 'file' => '', 'line' => '', 'args' => []];
@@ -97,7 +100,7 @@ public function printTrace(Throwable $e): void
             $traceStr .= "  <comment>$i)</end> <red>$symbol</end><comment>($args)</end>";
             if ('' !== $trace['file']) {
                 $file      = realpath($trace['file']);
-                $traceStr .= "<eol/>     <yellow>at $file</end><white>:{$trace['line']}</end><eol/>";
+                $traceStr .= "<eol/>     <yellow>" . t('at') . " $file</end><white>:{$trace['line']}</end><eol/>";
             }
         }
 
@@ -185,7 +188,7 @@ protected function showHelp(string $for, array $items, string $header = '', stri
             $this->writer->help_header($header, true);
         }
 
-        $this->writer->eol()->help_category($for . ':', true);
+        $this->writer->eol()->help_category(t($for) . ':', true);
 
         if (empty($items)) {
             $this->writer->help_text('  (n/a)', true);
@@ -229,7 +232,7 @@ public function showUsage(string $usage): self
         $usage = str_replace('$0', $_SERVER['argv'][0] ?? '[cmd]', $usage);
 
         if (!str_contains($usage, ' ## ')) {
-            $this->writer->eol()->help_category('Usage Examples:', true)->colors($usage)->eol();
+            $this->writer->eol()->help_category(t('Usage Examples') . ':', true)->colors($usage)->eol();
 
             return $this;
         }
@@ -246,7 +249,7 @@ public function showUsage(string $usage): self
             return str_pad('# ', $maxlen - array_shift($lines), ' ', STR_PAD_LEFT);
         }, $usage);
 
-        $this->writer->eol()->help_category('Usage Examples:', true)->colors($usage)->eol();
+        $this->writer->eol()->help_category(t('Usage Examples') . ':', true)->colors($usage)->eol();
 
         return $this;
     }
@@ -261,11 +264,11 @@ public function showCommandNotFound(string $attempted, array $available): self
             }
         }
 
-        $this->writer->error("Command $attempted not found", true);
+        $this->writer->error(t('Command %s not found', [$attempted]), true);
         if ($closest) {
             asort($closest);
             $closest = key($closest);
-            $this->writer->bgRed("Did you mean $closest?", true);
+            $this->writer->bgRed(t('Did you mean %s?', [$closest]), true);
         }
 
         return $this;
diff --git a/src/Helper/Shell.php b/src/Helper/Shell.php
index 3666d5d..d6dc227 100644
--- a/src/Helper/Shell.php
+++ b/src/Helper/Shell.php
@@ -13,6 +13,7 @@
 
 use Ahc\Cli\Exception\RuntimeException;
 
+use function Ahc\Cli\t;
 use function fclose;
 use function function_exists;
 use function fwrite;
@@ -99,7 +100,7 @@ public function __construct(protected string $command, protected ?string $input
     {
         // @codeCoverageIgnoreStart
         if (!function_exists('proc_open')) {
-            throw new RuntimeException('Required proc_open could not be found in your PHP setup.');
+            throw new RuntimeException(t('Required proc_open could not be found in your PHP setup.'));
         }
         // @codeCoverageIgnoreEnd
 
@@ -181,7 +182,7 @@ protected function checkTimeout(): void
         if ($executionDuration > $this->processTimeout) {
             $this->kill();
 
-            throw new RuntimeException('Timeout occurred, process terminated.');
+            throw new RuntimeException(t('Timeout occurred, process terminated.'));
         }
         // @codeCoverageIgnoreStart
     }
@@ -216,7 +217,7 @@ public function setOptions(
     public function execute(bool $async = false, ?array $stdin = null, ?array $stdout = null, ?array $stderr = null): self
     {
         if ($this->isRunning()) {
-            throw new RuntimeException('Process is already running.');
+            throw new RuntimeException(t('Process is already running.'));
         }
 
         $this->descriptors      = $this->prepareDescriptors($stdin, $stdout, $stderr);
@@ -234,7 +235,7 @@ public function execute(bool $async = false, ?array $stdin = null, ?array $stdou
 
         // @codeCoverageIgnoreStart
         if (!is_resource($this->process)) {
-            throw new RuntimeException('Bad program could not be started.');
+            throw new RuntimeException(t('Bad program could not be started.'));
         }
         // @codeCoverageIgnoreEnd
 
diff --git a/src/IO/Interactor.php b/src/IO/Interactor.php
index 9112383..b7af721 100644
--- a/src/IO/Interactor.php
+++ b/src/IO/Interactor.php
@@ -15,6 +15,7 @@
 use Ahc\Cli\Output\Writer;
 use Throwable;
 
+use function Ahc\Cli\t;
 use function array_keys;
 use function array_map;
 use function count;
@@ -312,7 +313,7 @@ public function choices(string $text, array $choices, $default = null, bool $cas
      */
     public function prompt(string $text, $default = null, ?callable $fn = null, int $retry = 3): mixed
     {
-        $error  = 'Invalid value. Please try again!';
+        $error  = t('Invalid value. Please try again!');
         $hidden = func_get_args()[4] ?? false;
         $readFn = ['read', 'readHidden'][(int) $hidden];
 
@@ -370,7 +371,7 @@ protected function listOptions(array $choices, $default = null, bool $multi = fa
             $this->writer->eol()->choice(str_pad("  [$choice]", $maxLen + 6))->answer($desc);
         }
 
-        $label = $multi ? 'Choices (comma separated)' : 'Choice';
+        $label = t($multi ? 'Choices (comma separated)' : 'Choice');
 
         $this->writer->eol()->question($label);
 
diff --git a/src/Input/Command.php b/src/Input/Command.php
index 0cfcf3b..bcefe31 100644
--- a/src/Input/Command.php
+++ b/src/Input/Command.php
@@ -21,12 +21,12 @@
 use Ahc\Cli\Output\Writer;
 use Closure;
 
+use function Ahc\Cli\t;
 use function array_filter;
 use function array_keys;
 use function end;
 use function explode;
 use function func_num_args;
-use function sprintf;
 use function str_contains;
 use function strstr;
 
@@ -83,9 +83,9 @@ public function __construct(
      */
     protected function defaults(): self
     {
-        $this->option('-h, --help', 'Show help')->on([$this, 'showHelp']);
-        $this->option('-V, --version', 'Show version')->on([$this, 'showVersion']);
-        $this->option('-v, --verbosity', 'Verbosity level', null, 0)->on(
+        $this->option('-h, --help', t('Show help'))->on([$this, 'showHelp']);
+        $this->option('-V, --version', t('Show version'))->on([$this, 'showVersion']);
+        $this->option('-v, --verbosity', t('Verbosity level'), null, 0)->on(
             fn () => $this->set('verbosity', ($this->verbosity ?? 0) + 1) && false
         );
 
@@ -196,7 +196,7 @@ public function argument(string $raw, string $desc = '', $default = null): self
         $argument = new Argument($raw, $desc, $default);
 
         if ($this->_argVariadic) {
-            throw new InvalidParameterException('Only last argument can be variadic');
+            throw new InvalidParameterException(t('Only last argument can be variadic'));
         }
 
         if ($argument->variadic()) {
@@ -303,9 +303,7 @@ protected function handleUnknown(string $arg, ?string $value = null): mixed
 
         // Has some value, error!
         if ($values) {
-            throw new RuntimeException(
-                sprintf('Option "%s" not registered', $arg)
-            );
+            throw new RuntimeException(t('Option "%s" not registered', [$arg]));
         }
 
         // Has no value, show help!
@@ -358,13 +356,13 @@ public function showDefaultHelp(): mixed
             $io->logo($logo, true);
         }
 
-        $io->help_header("Command {$this->_name}, version {$this->_version}", true)->eol();
+        $io->help_header(t('Command') . " {$this->_name}, " . t('version') . " {$this->_version}", true)->eol();
         $io->help_summary($this->_desc, true)->eol();
-        $io->help_text('Usage: ')->help_example("{$this->_name} [OPTIONS...] [ARGUMENTS...]", true);
+        $io->help_text(t('Usage') . ': ')->help_example("{$this->_name} " . t('[OPTIONS...] [ARGUMENTS...]'), true);
 
         $helper
             ->showArgumentsHelp($this->allArguments())
-            ->showOptionsHelp($this->allOptions(), '', 'Legend: <required> [optional] variadic...');
+            ->showOptionsHelp($this->allOptions(), '', t('Legend: <required> [optional] variadic...'));
 
         if ($this->_usage) {
             $helper->showUsage($this->_usage);
diff --git a/src/Input/Parameter.php b/src/Input/Parameter.php
index 46236ff..71088b9 100644
--- a/src/Input/Parameter.php
+++ b/src/Input/Parameter.php
@@ -13,10 +13,10 @@
 
 use Ahc\Cli\Helper\InflectsString;
 
+use function Ahc\Cli\t;
 use function json_encode;
 use function ltrim;
 use function strpos;
-use function sprintf;
 
 /**
  * Cli Parameter.
@@ -84,7 +84,7 @@ public function desc(bool $withDefault = false): string
             return $this->desc;
         }
 
-        return ltrim(sprintf('%s [default: %s]', $this->desc, json_encode($this->default)));
+        return ltrim(t('%1$s [default: %2$s]', [$this->desc, json_encode($this->default)]));
     }
 
     /**
diff --git a/src/Input/Parser.php b/src/Input/Parser.php
index 42977ca..3717be0 100644
--- a/src/Input/Parser.php
+++ b/src/Input/Parser.php
@@ -16,6 +16,7 @@
 use Ahc\Cli\Helper\Normalizer;
 use InvalidArgumentException;
 
+use function Ahc\Cli\t;
 use function array_diff_key;
 use function array_filter;
 use function array_key_exists;
@@ -24,7 +25,6 @@
 use function count;
 use function in_array;
 use function reset;
-use function sprintf;
 use function substr;
 
 /**
@@ -221,9 +221,7 @@ protected function validate(): void
                 [$name, $label] = [$item->long(), 'Option'];
             }
 
-            throw new RuntimeException(
-                sprintf('%s "%s" is required', $label, $name)
-            );
+            throw new RuntimeException(t('%1$s "%2$s" is required', [$label, $name]));
         }
     }
 
@@ -264,9 +262,9 @@ public function unset(string $name): self
     protected function ifAlreadyRegistered(Parameter $param): void
     {
         if ($this->registered($param->attributeName())) {
-            throw new InvalidParameterException(sprintf(
+            throw new InvalidParameterException(t(
                 'The parameter "%s" is already registered',
-                $param instanceof Option ? $param->long() : $param->name()
+                [$param instanceof Option ? $param->long() : $param->name()]
             ));
         }
     }
diff --git a/src/Output/Color.php b/src/Output/Color.php
index 4111038..c5becdb 100644
--- a/src/Output/Color.php
+++ b/src/Output/Color.php
@@ -13,13 +13,13 @@
 
 use Ahc\Cli\Exception\InvalidArgumentException;
 
+use function Ahc\Cli\t;
 use function array_intersect_key;
 use function constant;
 use function defined;
 use function lcfirst;
 use function method_exists;
 use function preg_match_all;
-use function sprintf;
 use function str_ireplace;
 use function str_replace;
 use function stripos;
@@ -198,12 +198,12 @@ public static function style(string $name, array $style): void
         $style = array_intersect_key($style, $allow);
 
         if (empty($style)) {
-            throw new InvalidArgumentException('Trying to set empty or invalid style');
+            throw new InvalidArgumentException(t('Trying to set empty or invalid style'));
         }
 
         $invisible = (isset($style['bg']) && isset($style['fg']) && $style['bg'] === $style['fg']);
         if ($invisible && method_exists(static::class, $name)) {
-            throw new InvalidArgumentException('Built-in styles cannot be invisible');
+            throw new InvalidArgumentException(t('Built-in styles cannot be invisible'));
         }
 
         static::$styles[$name] = $style;
@@ -220,7 +220,7 @@ public static function style(string $name, array $style): void
     public function __call(string $name, array $arguments): string
     {
         if (!isset($arguments[0])) {
-            throw new InvalidArgumentException('Text required');
+            throw new InvalidArgumentException(t('Text required'));
         }
 
         [$name, $text, $style] = $this->parseCall($name, $arguments);
@@ -235,11 +235,7 @@ public function __call(string $name, array $arguments): string
         }
 
         if (!method_exists($this, $name)) {
-            if (!self::$enabled || getenv('NO_COLOR')) {
-                return $text;
-            }
-
-            throw new InvalidArgumentException(sprintf('Style "%s" not defined', $name));
+            throw new InvalidArgumentException(t('Style "%s" not defined', [$name]));
         }
 
         return $this->{$name}($text, $style);
diff --git a/src/Output/ProgressBar.php b/src/Output/ProgressBar.php
index dcb4e27..b9593c0 100644
--- a/src/Output/ProgressBar.php
+++ b/src/Output/ProgressBar.php
@@ -14,6 +14,7 @@
 use Ahc\Cli\Helper\Terminal;
 use UnexpectedValueException;
 
+use function Ahc\Cli\t;
 use function count;
 use function implode;
 use function in_array;
@@ -133,7 +134,7 @@ public function option(string|array $key, ?string $value = null): self
     {
         if (is_string($key)) {
             if (empty($value)) {
-                throw new UnexpectedValueException('configuration option value is required');
+                throw new UnexpectedValueException(t('Configuration option value is required'));
             }
 
             $key = [$key => $value];
@@ -163,11 +164,13 @@ public function current(int $current, string $label = '')
     {
         if ($this->total == 0) {
             // Avoid dividing by 0
-            throw new UnexpectedValueException('The progress total must be greater than zero.');
+            throw new UnexpectedValueException(t('The progress total must be greater than zero.'));
         }
 
         if ($current > $this->total) {
-            throw new UnexpectedValueException(sprintf('The current (%d) is greater than the total (%d).', $current, $this->total));
+            throw new UnexpectedValueException(
+                t('The current (%1$d) is greater than the total (%2$d).', [$current, $this->total])
+            );
         }
 
         $this->drawProgressBar($current, $label);
diff --git a/src/Output/Table.php b/src/Output/Table.php
index 41e6303..dbcc059 100644
--- a/src/Output/Table.php
+++ b/src/Output/Table.php
@@ -14,6 +14,7 @@
 use Ahc\Cli\Exception\InvalidArgumentException;
 use Ahc\Cli\Helper\InflectsString;
 
+use function Ahc\Cli\t;
 use function array_column;
 use function array_fill_keys;
 use function array_keys;
@@ -24,7 +25,6 @@
 use function is_array;
 use function max;
 use function reset;
-use function sprintf;
 use function str_repeat;
 use function trim;
 
@@ -107,7 +107,7 @@ protected function normalize(array $rows): array
 
         if (!is_array($head)) {
             throw new InvalidArgumentException(
-                sprintf('Rows must be array of assoc arrays, %s given', gettype($head))
+                t('Rows must be array of assoc arrays, %s given', [gettype($head)])
             );
         }
 
diff --git a/src/functions.php b/src/functions.php
new file mode 100644
index 0000000..5de8ae9
--- /dev/null
+++ b/src/functions.php
@@ -0,0 +1,23 @@
+<?php
+
+/*
+ * This file is part of the PHP-CLI package.
+ *
+ * (c) Jitendra Adhikari <jiten.adhikary@gmail.com>
+ *     <https://github.com/adhocore>
+ *
+ * Licensed under MIT license.
+ */
+
+namespace Ahc\Cli;
+
+/**
+ * Translates a message.
+ */
+function t(string $text, array $args = []): string
+{
+    $translations = Application::$locales[Application::$locale] ?? [];
+    $text         = $translations[$text] ?? $text;
+
+    return sprintf($text, ...$args);
+}
diff --git a/tests/ApplicationTest.php b/tests/ApplicationTest.php
index 4283d0f..083f4c9 100644
--- a/tests/ApplicationTest.php
+++ b/tests/ApplicationTest.php
@@ -18,6 +18,8 @@
 use PHPUnit\Framework\TestCase;
 use Throwable;
 
+use function Ahc\Cli\t;
+
 class ApplicationTest extends TestCase
 {
     protected static $in = __DIR__ . '/input.test';
@@ -326,6 +328,46 @@ public function test_on_exception()
         $app->handle(['test', 'cmd']);
     }
 
+    public function test_default_translations()
+    {
+        $this->assertSame('Show version', t('Show version'));
+        $this->assertSame('Verbosity level [default: 0]', t('%1$s [default: %2$s]', ['Verbosity level', 0]));
+        $this->assertSame('Command "rmdir" already added', t('Command "%s" already added', ['rmdir']));
+    }
+
+    public function test_custom_translations(): void
+    {
+        Application::addLocale('fr', [
+            'Show version' => 'Afficher la version',
+            '%1$s [default: %2$s]' => '%1$s [par défaut: %2$s]',
+            'Command "%s" already added' => 'La commande "%s" a déjà été ajoutée'
+        ], true);
+
+        $this->assertSame('Afficher la version', t('Show version'));
+        $this->assertSame('Niveau de verbosite [par défaut: 0]', t('%1$s [default: %2$s]', ['Niveau de verbosite', 0]));
+        $this->assertSame('La commande "rmdir" a déjà été ajoutée', t('Command "%s" already added', ['rmdir']));
+
+        // untranslated key
+        $this->assertSame('Show help', t('Show help'));
+    }
+
+    public function test_app_translated()
+    {
+        $app = $this->newApp('test');
+        $app->addLocale('fr', [
+            'Show version' => 'Afficher la version',
+            'Verbosity level' => 'Niveau de verbocité',
+            '%1$s [default: %2$s]' => '%s [par défaut: %s]',
+        ], true);
+        $app->command('rmdir');
+
+        $app->handle(['test', 'rmdir', '--help']);
+        $o = file_get_contents(static::$ou);
+
+        $this->assertStringContainsString('Afficher la version', $o);
+        $this->assertStringContainsString('Niveau de verbocité [par défaut: 0]', $o);
+    }
+
     protected function newApp(string $name, string $version = '')
     {
         $app = new Application($name, $version ?: '0.0.1', fn () => false);
diff --git a/tests/Output/ProgressBarTest.php b/tests/Output/ProgressBarTest.php
index 3a4b5d8..c8c1e07 100644
--- a/tests/Output/ProgressBarTest.php
+++ b/tests/Output/ProgressBarTest.php
@@ -78,6 +78,7 @@ public function getIterator(): Traversable
         $this->assertNotNull((new Terminal)->height());
 
         $this->expectException(UnexpectedValueException::class);
+        $this->expectExceptionMessage('The current (2) is greater than the total (1).');
         (new ProgressBar(1))->current(2);
     }
 }