There are five subtests which include: conversational & expository speech, auditory comprehension, oral expression, reading, and writing.
The Boston Diagnostic Aphasia Examination provides a comprehensive exploration of a range of communicative abilities.
[3] The Examination is designed to go beyond simple functional definitions of aphasia into the components of language dysfunctions (symptoms) that have been shown to underlie the various aphasic syndromes.
The test is divided into five subtests and include assessment of conversation and expository speech (simple social responses, free conversation, and picture description), auditory comprehension (at the word-level, sentence level, and complex ideational material), oral expression (automatized sequences, repetition, and naming), reading (basic symbol recognition, number matching, word identification-picture-word matching, oral reading, and reading comprehension), and writing (mechanics, encoding skills, written picture naming, and narrative writing).
[citation needed] Validity: A discriminant analysis comparing "unambiguous exemplars of a single syndrome" was carried out.
In Depth Review of the Boston Diagnostic Aphasia Examination (BDAE) - Stroke Engine.