diff --git a/includes/functions.php b/includes/functions.php
index 2833564..d7ee59f 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -29,4 +29,42 @@ function userPath(
     return USERS_PATH .
         '/' .
         usernameToFolder($username);
-}
\ No newline at end of file
+}
+
+function slug(string $value): string
+{
+    $value = strtolower(trim($value));
+
+    $value = preg_replace(
+        '/[^a-z0-9]+/',
+        '_',
+        $value
+    );
+
+    return trim($value, '_');
+}
+
+function languagePath(
+    string $user,
+    string $language
+): string {
+
+    return userPath($user)
+        . '/languages/'
+        . slug($language);
+}
+
+function listPath(
+    string $user,
+    string $language,
+    string $list
+): string {
+
+    return languagePath(
+        $user,
+        $language
+    )
+    . '/lists/'
+    . slug($list)
+    . '.json';
+}