complex sentence
MediumFormal, Academic, Educational
Definition
Meaning
A sentence containing one independent clause and at least one dependent clause.
In linguistics and grammar, a sentence structure where a main clause is combined with one or more subordinate clauses, which cannot stand alone as complete sentences. The subordinate clauses are typically introduced by subordinating conjunctions (e.g., because, although, when) or relative pronouns (e.g., who, which, that).
Linguistics
Semantic Notes
The term is primarily technical/grammatical. In everyday speech, people might refer to a 'long or complicated sentence' but not specifically a 'complex sentence' unless discussing grammar. Do not confuse with 'compound sentence' (multiple independent clauses) or 'compound-complex sentence' (both independent and dependent clauses).
Dialectal Variation
British vs American Usage
Differences
No significant differences in definition or core usage. Minor variations in preferred example conjunctions or relative pronouns are stylistic, not systematic.
Connotations
Neutral technical term in both varieties.
Frequency
Equally common in educational and linguistic contexts in both regions.
Vocabulary
Collocations
Grammar
Valency Patterns
[Independent Clause] + [Subordinating Conjunction] + [Dependent Clause][Dependent Clause] + , + [Independent Clause]Vocabulary
Synonyms
Neutral
Weak
Vocabulary
Antonyms
Usage
Context Usage
Business
Rare, except in training or document clarity discussions: 'Avoid overly complex sentences in the client report.'
Academic
Common in linguistics, grammar, and writing instruction: 'The study analysed the acquisition of complex sentences in L2 learners.'
Everyday
Uncommon in casual conversation. Might be used by teachers/parents: 'Can you write a complex sentence using "although"?'
Technical
Core term in grammar and computational linguistics: 'The parser failed to deconstruct the complex sentence.'
Examples
By Part of Speech
verb
British English
- The tutor asked the students to complexify their simple sentences.
- Good writers often complex their prose as they advance.
American English
- The tutor asked the students to complexify their simple sentences.
- Good writers often complex their prose as they advance.
adverb
British English
- The paragraph was complexly constructed.
- He writes complexly yet clearly.
American English
- The paragraph was complexly constructed.
- He writes complexly yet clearly.
adjective
British English
- She struggled with the complex sentence structure.
- This is a more complex sentence than the previous one.
American English
- She struggled with the complex sentence structure.
- This is a more complex sentence than the previous one.
Examples
By CEFR Level
- I eat lunch when I am hungry.
- She is happy because she has a cat.
- Although it was expensive, we bought the tickets.
- The book that I borrowed from you is very interesting.
- Provided that you finish your work, you may join us for the film.
- The scientist, whose research was groundbreaking, received an award.
- Notwithstanding the considerable financial hurdles they faced, the entrepreneurs proceeded with the venture.
- The policy, which had been drafted in response to mounting public pressure, was ultimately ratified by parliament.
Learning
Memory Aids
Mnemonic
COMPLEX sentence has an EX-tra clause that is not independent (it's EX-cluded from standing alone).
Conceptual Metaphor
A MAIN LEADER (independent clause) with one or more SUPPORTING ASSISTANTS (dependent clauses) who cannot work alone.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not translate as 'сложное предложение' in the sense of 'difficult sentence'. In Russian grammar, 'сложное предложение' is a broader term covering both compound and complex sentences. The direct equivalent is 'сложноподчинённое предложение'.
- Avoid confusing with 'compound sentence' ('сложносочинённое предложение').
Common Mistakes
- Using a comma to join two independent clauses and calling it a complex sentence (that's a comma splice, often within a compound sentence).
- Thinking any long sentence is a complex sentence (it could be compound or compound-complex).
- Forgetting the comma when the dependent clause comes first: 'Because it was raining we stayed home.' (Missing comma after 'raining').
Practice
Quiz
Which of the following is a complex sentence?
FAQ
Frequently Asked Questions
No. 'Complex sentence' is a precise grammatical term for a specific structure. 'Complicated sentence' is a vague descriptive term for any sentence that is hard to understand.
Yes. A complex sentence can have one independent clause and multiple dependent clauses (e.g., 'After I finished work, which was late, I went home because I was tired.').
A complex sentence has one independent clause and at least one dependent clause. A compound-complex sentence has at least two independent clauses and at least one dependent clause.
A comma is typically used when the dependent clause comes before the independent clause (e.g., 'When he arrives, we will eat.'). When the independent clause comes first, a comma is usually not needed (e.g., 'We will eat when he arrives.').