The most common misunderstanding about grammar in IELTS: candidates think it's about avoiding mistakes. It's not. It's about demonstrating range — the ability to use different grammatical structures, not just simple ones delivered accurately.
Range comes first — accuracy is assessed within that range
The official IELTS band descriptors assess Grammatical Range separately from Accuracy. Band 5 is described as using "only a limited range of structures". Band 7 uses "a variety of complex structures". Band 9 uses these "flexibly and accurately".
An important nuance: errors that do not cause misunderstanding are penalised less heavily than errors that obscure meaning. Using complex structures with occasional minor errors is better than using only simple structures with no errors at all.
These three structures signal grammatical range immediately
One of these per answer is enough to signal range. Two is ideal. Using all three in a single answer can start to sound forced.
Self-correcting shows awareness — but too much kills fluency
Self-correction is actually noted positively in the IELTS band descriptors when it improves accuracy. But frequent self-correction — changing words mid-sentence repeatedly — is recorded as a hesitation pattern and penalises fluency. Correct real errors; don't over-edit while speaking.