this person is called a mute.
What is the english word for not being able to breastfeed the child?
The word for not being able to explain a theory is "incomprehensible."
The word for not being able to explain oneself is "inarticulate" or "incoherent."
The term for not being able to remember a word is "tip-of-the-tongue phenomenon."
you might not be able to get the child to talk about their problem.
The suffix -worthy means suitable for or suited to.
Unable
Unobtainable.
Precognition.
flightless
Inextricable
Being able to talk to someone who's far away.