Complex Sentences for IELTS Band 7+: A Complete Guide

"Uses a variety of complex structures" appears in the Band 7 descriptors for Grammatical Range and Accuracy. Many students interpret this as writing long, complicated sentences. That's wrong—and it often backfires.

In IELTS, "complex structure" doesn't mean "complicated." It means "made up of more than one part." The good news: you probably already use some complex structures without realizing it.

This guide shows you which structures count as "complex," how to use them correctly, and how to demonstrate range without risking errors.

What "Complex" Actually Means

A complex grammatical structure has multiple parts working together. This includes:

• Complex sentences (multiple clauses)
• Complex noun phrases (nouns with modifiers)
• Complex verb phrases (verbs with auxiliaries or modals)
• Complex verb patterns (verbs followed by specific structures)

You don't need to use only complex sentences. Using a variety of these structures demonstrates the grammatical range examiners want to see.

Complex Sentences: The Basics

Simple Sentence

One independent clause with subject + verb:

Technology improves education.

Compound Sentence

Two independent clauses joined by coordinating conjunction (and, but, or, so, yet):

Technology improves education, and it creates new opportunities.

Complex Sentence

One independent clause + one or more dependent clauses:

Technology improves education because it provides access to information.
Although technology has benefits, some people remain skeptical.

Compound-Complex Sentence

Two or more independent clauses + at least one dependent clause:

While technology improves education, it also raises concerns, and governments must address these issues.

Types of Complex Sentences for IELTS

1. Cause/Effect Clauses

Conjunctions: because, since, as, so...that

Examples:

Many students struggle with writing because they lack practice.
Since technology has become essential, schools must integrate it.
The problem is so severe that immediate action is required.

2. Contrast/Concession Clauses

Conjunctions: although, though, even though, while, whereas

Examples:

Although some people oppose this view, the evidence supports it.
While cities offer more opportunities, rural areas provide better quality of life.
Urban populations are increasing, whereas rural populations are declining.

3. Conditional Clauses

Conjunctions: if, unless, provided that, as long as

Examples:

If governments invest in education, economic growth will follow.
This problem will persist unless action is taken.
People can succeed provided that they work consistently.

4. Time Clauses

Conjunctions: when, while, before, after, since, until

Examples:

When students receive feedback, they improve more quickly.
Economic growth has accelerated since the reforms were introduced.
The situation will worsen until the government intervenes.

5. Relative Clauses

Pronouns: who, which, that, whose, where

Examples:

Students who receive regular feedback improve faster.
Technology, which has transformed communication, continues to evolve.
The city where I grew up has changed significantly.

Complex Noun Phrases

Complex noun phrases are often overlooked but are highly effective for demonstrating range.

Basic Noun Phrase

the problem

Complex Noun Phrases

With adjectives:

the serious environmental problem

With prepositional phrases:

the problem of air pollution in urban areas

With relative clauses:

the problem that affects millions of people

With participles:

the problem facing modern cities
the problem caused by industrial growth

Examples in Context

Simple:

Students need support.

Complex noun phrase:

Students who struggle with writing need additional support from teachers and technology.

Simple:

Technology has effects on education.

Complex noun phrase:

The rapid development of educational technology has significant implications for traditional teaching methods.

Complex Verb Phrases

Verb phrases with modal verbs and passive voice show grammatical sophistication.

Modal Verbs

Governments should invest more in education.
Technology could transform the healthcare industry.
This problem might have been prevented with better planning.

Passive Voice

Education is provided by the government.
New policies have been implemented to address this issue.
The data was collected from multiple sources.

Combined Modals and Passives

This problem could be addressed through better policies.
More research should be conducted before conclusions are drawn.
The results may have been influenced by external factors.

Complex Verb Patterns

Certain verbs require specific grammatical patterns. Using these correctly demonstrates advanced grammar knowledge.

Verb + to-infinitive

The government decided to implement new policies.
Many people tend to underestimate this problem.
Research appears to suggest a correlation.

Verb + -ing

Many countries have considered introducing stricter regulations.
People avoid discussing controversial topics.
The report suggests increasing investment.

Verb + object + to-infinitive

The policy enabled students to access better resources.
Technology allows people to communicate instantly.
Governments should encourage companies to invest in research.

Verb + object + -ing

I can't imagine society functioning without technology.
This involves students completing multiple assessments.

How to Use Complex Structures Effectively

Don't Overdo It

You don't need complex structures in every sentence. A good essay mixes simple, compound, and complex sentences.

Ineffective (too complex):

Although many people who live in cities believe that the government, which is responsible for urban planning, should have implemented policies that could have prevented the problems that are now affecting millions of residents who struggle with transportation issues, the reality is that the situation, which has been developing for decades, requires solutions that address multiple factors that contribute to the current crisis.

Effective (varied):

Many urban residents blame the government for transportation problems. Although city planners have attempted various solutions, the situation has worsened over decades. Addressing this crisis requires tackling multiple interconnected factors.

Accuracy Over Complexity

The Band 7 descriptors require "frequent error-free sentences." If you can't use a complex structure correctly, don't use it.

Rule: Only use structures you can use accurately. A simple, correct sentence is better than a complex, incorrect one.

Natural Integration

Complex structures should feel natural, not forced. If a sentence sounds awkward, simplify it.

Forced:

The fact that technology has advanced is something that has changed society.

Natural:

Technological advancement has transformed society.

Practical Exercises

Exercise 1: Combine Sentences

Take two simple sentences and combine them into one complex sentence:

1. Technology improves communication. Some people prefer face-to-face interaction.
   → Although technology improves communication, some people prefer face-to-face interaction.

2. The government introduced new policies. Economic growth improved.
   → Economic growth improved after the government introduced new policies.

Exercise 2: Expand Noun Phrases

Take a simple noun phrase and expand it:

1. the problem → the problem of environmental degradation in developing countries
2. students → students who lack access to quality education
3. technology → technology that enables instant global communication

Exercise 3: Add Modals and Passives

Rewrite sentences using modal verbs and/or passive voice:

1. The government should address this issue. → This issue should be addressed by the government.
2. Technology changes education. → Education is being transformed by technology.

Checklist for Grammatical Range

When reviewing your essays, check for variety:

Sentence Types:

• Simple sentences (at least a few)
• Compound sentences (with and/but/so)
• Complex sentences (with because/although/if/when/who/which)

Complex Structures:

• Complex noun phrases (modifiers before and after nouns)
• Relative clauses (who/which/that)
• Passive voice (where appropriate)
• Modal verbs (should/could/might/may)

What to Avoid:

• Every sentence starting the same way
• Only simple sentences
• Only complex sentences (too heavy)
• Complex structures you're not confident using

Key Takeaways

1. "Complex" means multi-part—not complicated or confusing
2. Mix sentence types—simple, compound, and complex
3. Use complex noun phrases—they're often overlooked but effective
4. Include some passives and modals—they add sophistication
5. Accuracy matters more than complexity—don't use structures you can't control
6. Aim for natural variety—not forced complexity

The goal isn't to impress with complicated sentences. It's to show you can use English flexibly and accurately across different structures.

Not sure if your grammar shows enough range? BandWriteCoach analyzes your sentence structures and tells you exactly which complex patterns you're using well and which you could add.