Why complex sentences can hurt
Grammatical Range and Accuracy considers both range and accuracy. Complex structures can show ability, but repeated errors reduce clarity.
Many learners try to show complex structures by making sentences longer. If clauses, punctuation, agreement, and reference are unstable, the reader works harder.
Short answer: complexity must sit on accuracy. Stabilise frequent error patterns before adding more range.
Long sentences repeatedly create agreement, clause, or punctuation problems.
The idea is clear until sentences are combined.
The learner rereads generally and skips their recurring errors.
Grammatical Range and Accuracy considers both range and accuracy. Complex structures can show ability, but repeated errors reduce clarity.
Instead of studying grammar generally, extract the top three recurring errors from the learner's own writing.
If the issue is accuracy, do a sentence-control repair pass: shorten the sentence, repair it, then combine only one structure at a time.
These pages explain the Banfen Writing diagnostic and blocker-repair method, Task 1 overview, Task 2 development, and common score blockers.
If complex sentences leave the score flat, diagnose error patterns and sentence control first.