Grammar: Clauses & Phrases
Master main and subordinate clauses, and identify noun, verb, and adverb phrases to write more varied and sophisticated sentences.
Clauses: The Building Blocks of Sentences
A clause is a group of words containing a subject and a verb. Unlike a phrase, a clause contains both. The key distinction is between main clauses and subordinate clauses.
Main Clause (Independent Clause)
Makes complete sense on its own. It can stand alone as a sentence. Every complete sentence has at least one main clause.
The dog barked.
Subject: "the dog" / Verb: "barked" — complete sense alone.
She opened the door.
Subject: "she" / Verb: "opened" — complete sense alone.
Subordinate Clause (Dependent Clause)
Adds extra information but cannot stand alone as a sentence — it depends on a main clause to make sense.
because it heard a noise
Has a subject + verb, but is incomplete — needs a main clause.
although she was tired
Makes no sense alone — is dependent on a main clause.
Combining Clauses
A complete sentence can combine one main clause and one or more subordinate clauses:
The dog barked because it heard a noise.
Main clause (green) + subordinate clause (yellow), joined by subordinating conjunction "because".
Although she was tired, she opened the door.
Subordinate clause first (with a comma), then main clause.
Common Subordinating Conjunctions
Phrases: Groups of Words Without a Verb+Subject
A phrase is a group of words that works as a unit but does not contain both a subject and a finite verb. Phrases function as nouns, verbs, adjectives, or adverbs within sentences. Recognising them helps you write more varied, sophisticated sentences.
A noun phrase is built around a noun (the head noun) with words that describe or modify it. It can function as a subject, object, or complement in a sentence.
Simple
the dog
Extended
the large, grey dog with muddy paws
A verb phrase is built around the main verb, often including auxiliary verbs (helper verbs like "have", "was", "will", "could") that show tense, aspect, or modality.
Simple
She ran.
Complex
She had been running for an hour.
An adverb phrase functions like an adverb — it modifies a verb, adjective, or another adverb by providing information about time, place, manner, or degree.
Manner
She spoke with great clarity.
Time & Place
He arrived just before midnight at the old station.
Key Vocabulary
Main Clause
A clause that contains a subject and verb and makes complete sense on its own — it can stand as a sentence.
Subordinate Clause
A clause with a subject and verb that cannot stand alone — it depends on a main clause and is introduced by a subordinating conjunction.
Subordinating Conjunction
A word that introduces a subordinate clause and shows its relationship to the main clause (e.g., because, although, when, unless).
Complex Sentence
A sentence containing one main clause and at least one subordinate clause — the most common sentence type in formal writing.
Worked Examples
Example 1: Identifying Clauses
"Even though the storm had passed, the river remained dangerously high."
Analysis: "Even though the storm had passed" is the subordinate clause — "even though" is the subordinating conjunction; it cannot stand alone. "the river remained dangerously high" is the main clause — it makes complete sense alone. When the subordinate clause comes first, a comma separates it from the main clause.
Example 2: Identifying Phrases
"The ancient, crumbling lighthouse had been warning sailors for over a century."
Analysis:
Noun phrase: "The ancient, crumbling lighthouse" — head noun "lighthouse" with two adjectives.
Verb phrase: "had been warning" — past perfect continuous, showing ongoing past action.
Adverb phrase: "for over a century" — tells us for how long (time/duration).
Example 3: Using Subordinate Clauses for Effect
SIMPLE (less sophisticated)
"She was scared. She went anyway. She found the truth."
COMPLEX (more sophisticated)
"Although she was scared, she went anyway — and when she did, she finally found the truth she had been searching for."
Subordinate clauses allow you to show relationships between ideas (cause, contrast, time) within a single sentence, producing more mature, varied writing.
Knowledge Check
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Key Concepts Summary
- ●A clause has a subject + verb. A phrase does not contain both a subject and a finite verb.
- ●A main clause makes complete sense alone. A subordinate clause depends on a main clause.
- ●Subordinate clauses are introduced by subordinating conjunctions: because, although, when, unless, if, while.
- ●A noun phrase = noun + modifiers. A verb phrase = main verb + auxiliaries. An adverb phrase modifies a verb/adjective.
- ●Using complex sentences (main + subordinate clause) creates more sophisticated, varied writing.