I was wondering what do native speakers normally call someone who is unable to speak in modern English.
I know the words "dumb" and "mute which perhaps according to the dictionaries, it is dated and even impolite.
Also I need to know what do you call someone who is unable to speak and hear at the same time.
I wonder what is the safest and more common way to address such people.
Best Answer
As has been pointed out, dumb has fallen out of favor and the preferred term is mute. This is an example of the so-called euphemism treadmill; as you have pointed out, "dumb" used to be perfectly fine, but now it can seem offensive. Similarly moron and (I believe) retard used to be medical terms for people with IQs below a certain level, but now are only ever used as very offensive insults.
I would call someone who can neither hear nor speak a deaf-mute. And as Fumble pointed out, it is often better to refer to someone as a person rather than a collection of inabilities, so "a person who can't hear or speak" might be better.