Blind John has difficulty articulating the words verbally to tell Sally how much he loves her
Mute John has difficulty _______ the words in writing to tell Sally how much he loves her
Also do you say the words or his words as he can't think of them.
Another example to simplify the context.
Tom is 12 years old. His teacher tells his parents he is very good at articulating verbally ideas but has difficulty ..... the words to paper.