In php if you want to translate a text from one language to other language then you can use below code. you have to create a google api key for translate word.In this we should pass a source language code or target language code or a text string.

Use Below Code :

function translateText($source, $target, $text)
{
        $apiKey = 'xxxxxyCdGtTIxxxxxxfanlujqxxxxx';
        $url = 'https://www.googleapis.com/language/translate/v2?key=' . $apiKey . '&q=' . rawurlencode($text) . '&source='.$source.'&target='.$target.'';

        $handle = curl_init($url);
        curl_setopt($handle, CURLOPT_RETURNTRANSFER, true);
        $response = curl_exec($handle);                 
        $responseDecoded = json_decode($response, true);
        curl_close($handle);
        $response = (isset($responseDecoded['data']) && !empty($responseDecoded['data']))?$responseDecoded['data']['translations'][0]['translatedText']:'';
        return $response;
}

$data = translateText("en","it","Hello World");

Output :
Ciao mondo