Complex and Compound Sentences

Why Sentence Variety Matters

Grammatical Range and Accuracy is worth 25% of your IELTS score. Grammatical Range specifically means using a variety of sentence structures. An essay written entirely in simple sentences — even if they are grammatically correct — cannot score above Band 6 for this criterion.

Three Sentence Types

Simple sentence: One independent clause. "Air pollution is increasing."

Compound sentence: Two independent clauses joined by a coordinating conjunction (and, but, so, yet, or, for, nor). "Air pollution is increasing, and respiratory diseases are becoming more common."

Complex sentence: One independent clause and one dependent clause joined by a subordinating conjunction. "Although air pollution has worsened significantly, many governments have failed to implement effective regulations."

Subordinating Conjunctions — The Most Important List

Contrast: although, even though, while, whereas, despite the fact that Cause: because, since, as, given that, owing to the fact that Condition: if, unless, provided that, as long as, in the event that Time: when, whenever, after, before, once, as soon as, by the time Purpose: so that, in order that, in order to

How to Vary Your Sentences

Do not write three simple sentences in a row. After two simple sentences, combine the next idea into a complex sentence. A strong paragraph typically mixes all three sentence types.

Band Comparison

Band 5: "Social media is popular. Many people use it every day. It can be addictive. This is a problem."

Band 7: "Social media is extremely popular and many people use it daily. However, because it is designed to be addictive, it presents a significant challenge for mental health."

Band 9: "Although social media has undeniably transformed the way people communicate and access information, its algorithmically engineered addictiveness raises profound concerns for mental health, particularly among younger users who are still developing their capacity for self-regulation."

Common Mistakes

Run-on sentences — joining too many clauses with "and" repeatedly: "People use social media and it is addictive and it causes mental health problems and governments should regulate it."

Using "however" as a conjunction mid-sentence — "It is useful, however it is addictive" is wrong. Use "however" at the start of a new sentence or use "although" instead.