WrongMany students work part-time, they have less time to study.
RightMany students work part-time, so they have less time to study.
Two independent clauses cannot be joined by a comma alone — use «so», «because», «and», or a full stop.
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Grammar
Complex sentences
Band 7 asks for «a variety of complex structures» — but accuracy decides it, not length.
Why this moves your band
Grammatical Range does not reward complex sentences as such; it rewards complex sentences that are correct. Joining two independent clauses with a comma is the most common structural error.
The rule
- 1One main clause plus one subordinate clause is enough — a long sentence is not automatically a complex one.
- 2Add detail with «which / who / that» instead of starting a new sentence.
- 3Open some sentences with the subordinate clause: «Although…, …». That is the variety being marked.
Wrong and right
WrongAlthough the policy is expensive, but it saves money later.
RightAlthough the policy is expensive, it saves money later.
«Although» and «but» never appear together; pick one.
WrongThe city which is has a metro is growing fast.
RightThe city, which has a metro, is growing fast.
A «which» clause that adds extra information takes a comma on both sides.
Check after writing
- Are there any comma splices left?
- Does each clause have its own verb?
- Do at least two sentences open with a subordinate clause?
Practice
Pick one answer for each question — the right answer and the rule appear straight away. Nothing is saved.
1. the course was difficult, most students passed it.
2.The museum, opened in 1998, attracts thousands of visitors a year.
3.Teachers explain ideas clearly are remembered for years.
4.Which sentence is a complex sentence (a main clause plus a subordinate clause)?
5.Many people moved to the capital, made housing more expensive.
6. fewer people use cash, many small shops now accept cards.
Test your grammar in an essay
Write an essay and the AI grades it on Grammatical Range and Accuracy too, showing which mistake keeps coming back.