You are viewing a free preview of this lesson.
Subscribe to unlock all 10 lessons in this course and every other course on LearningBro.
One of the most reliable ways to push your IELTS writing and speaking score from Band 6 to Band 7 is to demonstrate confident, accurate use of complex sentences. The IELTS marking criteria for Grammatical Range and Accuracy explicitly reward candidates who produce "a variety of complex structures" with "frequent error-free sentences."
This lesson teaches you how to build complex sentences using subordinate (dependent) clauses — what they are, how they work, and where IELTS candidates most often go wrong.
A simple sentence has one independent clause:
The government increased taxes.
A compound sentence joins two independent clauses with a coordinating conjunction (and, but, or, so, yet):
The government increased taxes, and public spending rose.
A complex sentence contains one independent clause and at least one subordinate (dependent) clause:
Although the government increased taxes, public spending continued to decline.
The subordinate clause ("Although the government increased taxes") cannot stand on its own — it depends on the main clause for meaning.
These modify the verb in the main clause and answer questions like when?, why?, how?, and under what conditions?
They begin with subordinating conjunctions such as:
| Purpose | Conjunctions | Example |
|---|---|---|
| Time | when, while, before, after, since, until, as soon as | After the policy was introduced, crime rates fell. |
| Reason | because, since, as | Since unemployment is rising, consumer confidence has dropped. |
| Contrast | although, even though, whereas, while | Although the economy grew, inequality worsened. |
| Condition | if, unless, provided that | Unless governments act, pollution will intensify. |
| Purpose | so that, in order that | Subsidies were introduced so that farmers could survive. |
| Result | so … that, such … that | The drought was so severe that crops failed entirely. |
Band 6 vs Band 7 comparison:
Band 6: Pollution is increasing. The government should take action.
Band 7: Because pollution is increasing at an alarming rate, it is imperative that the government takes decisive action.
These function as the subject or object of a sentence:
What the research demonstrates is that exercise improves mental health.
Many experts believe that renewable energy will replace fossil fuels.
Common starters: that, what, whether, how, why, where
These modify a noun and are covered in detail in Lesson 4. A brief preview:
Countries that invest in education tend to have stronger economies.
Getting the punctuation right is important — errors here look careless to the examiner.
Although renewable energy is expensive, it offers long-term savings. ✅
Renewable energy offers long-term savings although it is expensive. ✅
China, which is the world's largest emitter, has pledged to reach carbon neutrality by 2060. ✅
❌ Although the government invested heavily in education. (Fragment — no main clause)
✅ Although the government invested heavily in education, literacy rates remained low.
❌ The population is growing resources are becoming scarce.
✅ The population is growing, and resources are becoming scarce.
✅ As the population is growing, resources are becoming scarce.
❌ Tourism brings economic benefits, it also causes environmental damage.
✅ Although tourism brings economic benefits, it also causes environmental damage.
✅ Tourism brings economic benefits; however, it also causes environmental damage.
❌ Although the economy improved, but unemployment remained high.
✅ Although the economy improved, unemployment remained high.
This error is extremely common among IELTS candidates — using although and but together. Choose one or the other, never both.
Cause: Because urban populations are increasing rapidly, traffic congestion has become a major problem in cities.
Contrast: Even though public transport has improved, traffic congestion remains a major problem in cities.
Condition: If governments fail to invest in infrastructure, traffic congestion will continue to worsen.
Use subordinate clauses to link data points:
While the number of cars increased steadily between 2000 and 2010, bicycle usage declined sharply during the same period.
Use them to develop arguments:
Although some argue that technology isolates individuals, the evidence suggests that social media has enabled new forms of community and connection.
The examiner wants to see a mix of simple, compound, and complex sentences. Do not write only complex sentences — that sounds unnatural. A good paragraph might have:
Rewrite the following pairs of simple sentences as complex sentences using an appropriate subordinating conjunction:
Many people move to cities for work. Rural areas are becoming depopulated. → Because many people move to cities for work, rural areas are becoming depopulated.
Online education is convenient. It lacks the social interaction of traditional classrooms. → Although online education is convenient, it lacks the social interaction of traditional classrooms.
The government banned single-use plastics. Marine pollution has decreased. → Since the government banned single-use plastics, marine pollution has decreased.
Automation increases efficiency. Many workers fear losing their jobs. → While automation increases efficiency, many workers fear losing their jobs.
Students study abroad. They gain a broader perspective. → When students study abroad, they gain a broader perspective.