Translate each given string in any language, while importing, with WP All Import (via Google Translate) - path should be wp-content/uploads/wpallimport/functions.php

function.php

function translate_field_with_google($text, $target_language = 'ro') {
//usage
// [translate_field_with_google({title[1]}, "ro")] where title[1] is the string, and "ro" is the lang.
    if (!empty($text)) {
        $api_key = 'YOUR_GOOGLE_TRANSLATE_KEY_HERE';
        $url = 'https://translation.googleapis.com/language/translate/v2?key=' . $api_key;
        $data = array('q' => $text, 'target' => $target_language);

        $options = array(
            'http' => array(
                'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
                'method'  => 'POST',
                'content' => http_build_query($data),
            ),
        );
        $context  = stream_context_create($options);
        $result = file_get_contents($url, false, $context);
        if ($result === FALSE) {
            return $text;
        }

        $response = json_decode($result, true);
        if (isset($response['data']['translations'][0]['translatedText'])) {
            return $response['data']['translations'][0]['translatedText'];
        } else {
            return $text;
        }
    }
    return $text; 
}