English Sentence Structure: Subordinate and Independent Clauses

Learn the difference between subordinate and independent clauses and use this knowledge to make your writing more fluid and lively!

Oftentimes, ESL students have difficulty distinguishing between independent and subordinate clauses. Sometimes they don’t even understand the difference between the sentence and the clause. If you really want to understand the difference between the two, then you should remember that there can be no sentence without a clause. One clause or more clauses constitute a sentence.

The Clause and the Sentence

What is a clause? A clause is a group of words containing a subject and a verb. That’s right, any subject-verb combination can create a clause:

  • Birds fly. (birds-subject + fly-verb = clause)

The reverse is also true: if there is no subject or no verb, there is no clause.

Clauses can be subordinate or independent. A subordinate clause is a group of words that has both a subject and a verb but cannot stand alone as a sentence. In contrast, an independent clause is a group of words that has both a subject and a verb but can stand alone as a sentence. For example:

  • after what she did to me (she-subject + did-verb = clause)

Does this clause seem complete to you? I bet it doesn’t! This clause lacks information. Since it doesn’t make sense alone, it is incomplete (subordinate). As such, it cannot form a sentence. It’s just an incomplete clause – a sentence fragment.

What about this one:

  • Tanya likes chocolate. (Tanya-subject + likes-verb + chocolate-object = clause)

This clause doesn’t lack any information. The object ‘chocolate’ makes it complete (‘Tanya likes’ is an incomplete thought and cannot form a sentence). This is an independent clause and can therefore form a simple sentence.

Now let’s move on to sentences. What is a sentence? A sentence is also a group of words, usually containing a subject and a verb, that expresses a complete thought. Sentences consist of clauses. Therefore, one independent clause is sufficient to form one simple sentence. For example:

  • Tanya has a beautiful cat. (Tanja-subject + has-verb + a beautiful cat-object = clause)

The object ‘a beautiful cat’ makes the clause complete. One complete/independent clause always forms a simple sentence. A subordinate clause, which is basically an incomplete thought, cannot form a sentence. Remember, it’s just a sentence fragment:

  • Tanya has. wrong (Has what?)

The best sentences usually combine different elements in all sorts of patterns. If you would like to create longer and more interesting sentences, you can join together a subordinate and an independent clause – or vice versa:

  • After what she did to me (incomplete thought-dependent/subordinate clause), I’ll never trust her again (complete thought-independent clause).

English sentence structureTypes of Subordinate Clauses

So far you have learned that subordinate clauses cannot stand alone as sentences because they don’t make complete sentence. To become complete, they have to tack themselves onto independent clauses:

  • If you would like me to help you (incomplete thought-subordinate/dependent clause), just give me a call (complete thought-independent clause).

So what is the function of subordinate clauses? They have three main purposes in sentences:

  • They describe nouns and pronouns.
  • They describe verbs, adjectives, or adverbs.
  • They act as subjects or objects inside another clause.

Subordinate Clauses Describing Nouns and Pronouns

Subordinate clauses can describe nouns and pronons. In other words, subordinate clauses may give the reader or listener more information about a noun or pronoun in the sentence. Here are some examples, with the subordinate clauses in italic:

  • The book that Tanya wroteis very entertaining. (that Tanya wrote describes the noun book)
  • Anyone who knows Tanya wellwill read the book. (who knows Tanya well describes the pronoun anyone)
  • The book includes some information that mightembarrass some of Tanya’s friends. (that might embarrass some of Tanya’s friends describes the noun information)

Subordinate clauses that describe nouns and pronouns are called adjectival or adjective clauses. Adjectival clauses perform the same function as single-word adjectives.

Subordinate Clauses Describing Verbs, Adjectives, and Adverbs

Subordinate clauses can also describe verbs, adjectives and adverbs. These clauses tell you how, when, where, or why something happened. For example:

  • Because Tanya censored herself, the book contains nothing about the exploding car. (Why does the book contain nothing about the exploding car?Because Tanya censored herself describes the verb contains)
  • We will probably find out more about Tanya’s love life when the movie version of her book is released. ( When will we find out more about Tanya’s love life? when the movie version of her book is releaseddescribes the verb will find out)
  • The government might prohibit sales of the book wherever international tensions make it dangerous. (wherever international tensions make it dangerousdescribes the verb may prohibit)
  • Jack is so angry that he may sue his wife. (How angry? that he may sue his wifedescribes the adverb so)

Subordinate clauses that describe verbs, adjectives, and adverbs are called adverbial clauses.

Subordinate Clauses Acting as Subjects or Objects Inside Another Clause

Subordinate clauses may sometimes do any job that a noun usually does in a sentence (they may substitute for a noun in the sentence). These clauses sometimes act as subjects or objects inside another clause. For example:

  • When Tanya’s book was writtenis a real mystery.(What is a real mystery? When Tanya’s book was written is the subject of the verb is)
  • No one knows whom Jack hired to redecorate his kitchen. (What does no one know? whom Jack hired to redecorate his kitchen is the object of the verb knows)

These clauses are called noun clauses. In the first example, the noun clause ‘When Tanya’s book was written’ is used as the subject of the verb is. In the second example, the noun clause ‘whom Jack hired to redecorate his kitchen’ is used as the object of the verb knows.

Untangling Subordinate and Independent Clauses

When you have to untangle one clause from another, follow these simple steps:

  • Find the subject-verb pairs.
  • Use your reading comprehension skills to determine whether the subject-verb pairs belong to the same thought or to different thoughts.

How many clauses can you find in this sentence?

SENTENCE: The book award that Tanya received comes with a hefty check.

SUBJECT-VERB PAIRS: the book award comes, Tanya received

UNTANGLED IDEAS: The book award comes with a hefty check. Tanya received the award.

CLAUSE Nr 1: The book award comes with a hefty check. (independent clause- complete thought)

CLAUSE Nr 2: that Tanya received (subordinate clause – incomplete thought)

The sentence is the basic means of written communication. It is also the largerst grammatical and the smallest communication unit. A good knowledge of sentence structure will make your writing interesting and help you avoid wordy and monotonous sentences.