For students sitting the exam from Turkey the score usually stalls on the verbal side, and it cannot be made up on the mathematics side because each section has its own ceiling.
Why not vocabulary
The diagnosis heard most often is vocabulary. Looked at through actual errors the picture differs: the student understands the passage and misreads the question.
Question stems are written in a compressed academic register. A stem asking for the main idea and one asking for the author's purpose want different answers, and read quickly the two look alike.
The fastest gain is in the conventions
The standard English conventions area is a closed set of rules: punctuation, agreement, tense consistency, connectors. It is finite and learnable.
For a student short of time the highest return per hour sits there. Reading comprehension improves slowly and through volume.
How to work on vocabulary
The exam tests words in context, meaning it wants the function of the word in that sentence rather than its dictionary meaning. Memorising lists therefore does not convert directly into score.
The more productive route is recording unfamiliar words met in worked questions, in the student's own sentence. That list is short and consists of words that actually appeared.
Pacing
Because each question comes with its own short paragraph, reading endurance is not decisive. What is decisive is the speed of recognising the question type.
Since question types arrive grouped, when one group becomes hard the next starts easy again. That knowledge makes abandoning a question at the end of a group a strategic move.
The order of study
Conventions first, then classifying question stems, then volume. Reversed, months are spent working questions while the score stands still.
Working on question stems is a heading of its own: for every wrong answer, first write what the stem was asking, then look for the answer.