Hi, the best expression for "How are you doing?" in French is "Comment allez vous?" or when you talk to a friend: "Comment vas tu?" About "Best Regards" the correct meaning is "Cordialement"

Hello, The most common formal expression is: Comment allez vous?

Comment ça va ? Commet tu vas ? Comment allez vous ? Ca roule ? Ca gaze ? Wesh, bien ou quoi ? Tranquille ? Y'a plusieurs manières de le dire （*＾3＾）

thanks , for your correction.

Hi, In your question you can't ask "how speak something". You may say "how to say…". Speak is used when you want to say for example "I speak english" or "I speak fluently". In chinese you can use 说 to say 您什么说… But not in english : say correspond to 讲.