The phrase "able to communicate only" is correct and usable in written English.
It can be used to specify a limitation in communication, indicating that the subject can communicate in a restricted manner or with certain constraints.
Example: "He is able to communicate only in sign language, which makes it challenging for him to interact with those who do not understand it."
Alternatives: "capable of communicating solely" or "restricted to communicating only".
He is able to communicate only with his mother, grandmother and lawyer.
At some point he will be able to communicate only by blinking an eye.
Mr. Bates said his brother was so busy the past three weeks as a pilot that they were able to communicate only by text.
In an interview last month she explained that her husband cannot walk or speak and is able to communicate only by nodding.
The prize for best actor went to Mathieu Amalric for his performance as a man crippled by a stroke and able to communicate only by blinking an eyelid in "The Diving Bell and the Butterfly".
Propped up in a wheelchair, able to communicate only by blinking his left eye (the other, in one especially nightmarish scene, has been sewn shut to prevent infection), he remains a sensualist, a bon vivant and a keen literary wit.
In today's competitive job market, pharmacists must be able to communicate not only with those in their field of expertise but also with others, including patients, corporate leaders, and budget directors.
"I want to be able to communicate, not only to the people who are at this conference, but [to] those who hear about the conference, how important the issues of poverty and concentrated poverty are and to try to provide a comprehensive understanding of these conditions and how they've changed over time," said Wilson.
After that, they would be able to communicate wirelessly only through a network that they were about to create themselves.
Their training and practice too often leaves them able to communicate effectively only with other planners and professionals, working in an abstract language that alienates them from people.
"One severe stutterer virtually lived the life of a nomad because he was able to communicate vocally only whenever he established himself in a new town," wrote Oliver Bloodstein, who did Johnson's fieldwork.
