Getting certain args in .Chatted + strings?

So I am detecting when a player chats with in a local script.

Player.Chatted:connect(function(Message)

end)

but how can I pick out certain things of that message and define them as a variable? I've tried things like:

Player.Chatted:connect(function(Message)
    if Message == "Hello " then
        --code
end)

but how do I get what's after "Hello ", so if the player says "Hello World" I can continue, but if they say "Hello foo" something else will happen, but mainly defining the 'extra' (world, bananas) as its own variable so like;

Args = string.sub() --?

Not that good with string. - any help would be appreciated.