wi-events/lang/en/validation.php

<?php

return [
    'attributes' => [
        'firstname' => 'Vorname',
        'lastname' => 'Nachname',
        'activity' => 'Funktion',
        'gender' => 'Geschlecht',
        'birthday' => 'Geburtsdatum',
        'address' => 'Straße & Hausnr',
        'zip' => 'PLZ',
        'location' => 'Ort',
        'phone' => 'Telefonnummer',
        'email' => 'E-Mail-Adresse',
        'agegroup' => 'Stufe',
        'emergency_phone' => 'Notfallkontakt',
        'group' => 'Stamm',
    ],
];