how to translate from language to another in c# ASP.NET?

Question

im working on a project  (Names Translator ) in c# ASP.NET

 

this is my code

public String Translate(String word)
{
    var toLanguage = "en";//English
    var fromLanguage = "ar";//Deutsch
    var url = $"https://translate.googleapis.com/translate_a/single?client=gtx&sl={fromLanguage}&tl={toLanguage}&dt=t&q={HttpUtility.UrlEncode(word)}";
    var webClient = new WebClient
    {
        Encoding = System.Text.Encoding.UTF8
    };
    var result = webClient.DownloadString(url);
    try
    {
        result = result.Substring(4, result.IndexOf("\"", 4, StringComparison.Ordinal) - 4);
        return result;
    }
    catch
    {
        return "Error";
    }
}

and its works for most names

but sometimes "google translate" translate the names literally

for example

the result will be 

He was authorized by Mohamed Ahmed 

????=he was authorized

it translate the name literally

when i go to google translate and translate the same name

it gives me the same wrong translation

but as you notice from the picture "khwlh muhamad ahmad next to red arrow" appear below  is what i want !

 how can i achive this ?

i need help ! thank you