Term for a person who can read but cannot write

I'm looking for a term to accurately describe a person who can only read but cannot write. While I'm primarily concerned with people who have never learned to write, I would also be interested in any additional terms used to represent people who have lost the ability to write as a result of disuse.

Both illiterate and unlettered imply an inability to read as well as to write.

Dysgraphia, per Dorland's Illustrated Medical Dictionary 31st Ed., is simply "difficulty in writing." Therefore, I disagree that this is a correct answer.

Agraphia is defined as:

"Impairment or loss of the ability to write; it takes two forms, one involving poor morphology of written letter forms and the other a reflection of the aphasia also observed in spoken language... Called also graphomotor aphasia"

I do think you need to carefully make a distinction between the person who never learned to write and those who have lost the ability to write. One may be a learning issue, whereas the other can be the result of a neurologic problem, such as a stroke. Agraphia and dysgraphia are terms that imply that the ability was once there, but is now either impaired or lost.

I don't know of a term that would cover the loss of the ability to write through disuse.

Dysgraphia is the condition of being unable to write; one who suffers from dysgraphia could be called dysgraphic.

Some dictionaries (1,2) list “able to read but unable to write” as a sense of semiliterate. However, two other senses of that word (“able to read and write on an elementary level” and “having limited knowledge or understanding”) might be more commonly understood.