diff --git a/tests/TranslatorTest.php b/tests/TranslatorTest.php
new file mode 100644
index 0000000..4564ae9
--- /dev/null
+++ b/tests/TranslatorTest.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Bazaar\Tests;
+
+use Bazaar\Support\Translator;
+use PHPUnit\Framework\TestCase;
+
+final class TranslatorTest extends TestCase
+{
+    private function translator(string $locale = 'en'): Translator
+    {
+        return new Translator(dirname(__DIR__) . '/resources/lang', $locale);
+    }
+
+    public function testEnglishIsTheDefault(): void
+    {
+        $this->assertSame('Shop', $this->translator()->get('nav.shop'));
+    }
+
+    public function testPolishCatalogResolves(): void
+    {
+        $this->assertSame('Sklep', $this->translator('pl')->get('nav.shop'));
+    }
+
+    public function testUnknownLocaleFallsBackToDefault(): void
+    {
+        $translator = $this->translator();
+        $translator->setLocale('de');
+        $this->assertSame('en', $translator->locale());
+        $this->assertSame('Shop', $translator->get('nav.shop'));
+    }
+
+    public function testMissingKeyReturnsTheKeyItself(): void
+    {
+        $this->assertSame('nav.doesNotExist', $this->translator()->get('nav.doesNotExist'));
+    }
+
+    public function testReplacementTokensAreSubstituted(): void
+    {
+        $this->assertSame('5 results', $this->translator()->get('catalog.resultsMany', ['count' => 5]));
+        $this->assertSame('5 wynikow', $this->translator('pl')->get('catalog.resultsMany', ['count' => 5]));
+    }
+
+    public function testSwitchingLocaleAtRuntime(): void
+    {
+        $translator = $this->translator('en');
+        $this->assertSame('Cart', $translator->get('nav.cart'));
+
+        $translator->setLocale('pl');
+        $this->assertSame('Koszyk', $translator->get('nav.cart'));
+    }
+
+    public function testSupportedLocales(): void
+    {
+        $this->assertTrue(Translator::isSupported('pl'));
+        $this->assertTrue(Translator::isSupported('en'));
+        $this->assertFalse(Translator::isSupported('fr'));
+    }
+}