Phrases and clauses are groups of words that can add meaning to sentences. However, they can sometimes be confusing because they work like parts of speech and contain more than one word.
A clause contains a subject and a verb. For example, “he is playing” is a clause. However, a phrase cannot stand alone as a sentence.
Subject and Predicate
English-language arts teachers spend a lot of time on helping students identify and use subjects and predicates. This is because these two elements are the fundamental parts of any complete sentence.
The subject of a sentence is the person or thing about whom or which something is being said. It is usually a noun or pronoun. A predicate is a verb phrase or clause that tells what the subject is doing, who the subject is, or what state the subject is in.
A predicate can also contain a complement or an adverbial modifier. In addition, some predicates can be collective; they can appear with multiple subjects. Examples of this include meet in the woods, surround the house and gather in the hallway.
Adjective and Adverbial Clauses
To recognize a phrase, you have to look for a subject and a verb. If you can’t identify one of those two, the words are a clause and not a phrase.
Adjective and adverbial clauses can trip up writers because they both work as specific parts of speech, but don’t always have a subject or verb. They may start with a relative pronoun, such as which, who, where, when, or whose.
This type of dependent clause adds more information to a noun or pronoun in a sentence. It can also modify another adjective or adverb in the sentence. The bright red ball that slipped from my hands bounced directly into the mud puddle. This is an adjective phrase that adds more information to the noun ball. It also modifies the verb slipped. This type of adjective clause is often used to describe the cause and effect of a situation. This can make the reader think about the circumstances in a new way.
Subordinate Clauses
A subordinate clause, or dependent clause, can’t stand on its own. Instead, it’s joined to an independent clause by subordinating conjunctions such as although, since, if, before, after, until, for (to), etc. It can also begin with relative pronouns such as that, which, who, whoever, whomever and whose.
A dependent clause can be either an adjective clause, adverb clause or noun clause. Adjective clauses are grouped together in this way to make the word or phrase more descriptive, and noun clauses act as modifiers of nouns.
The comma is used to separate an independent clause from a dependent clause, but the punctuation rules are slightly different for adverbs and nouns. It’s best to read your writing out loud and listen for the rhythm—you may find that phrases that look fine on screen sound confusing or long when spoken aloud.
Independent Clauses
The building block of a sentence, an independent clause expresses one complete thought. It includes a subject and a verb. A dependent clause, on the other hand, does not stand alone and must be connected to an independent clause with a subordinating or coordinating conjunction. An example of a dependent clause is a relative pronoun (who, whom, whose, which) or an infinitive phrase.
An independent marker word, such as and, although, moreover, likewise, more than, or even, can link two independent clauses together. A semicolon is required if the independent markers are joined with correlative conjunctions like both/and, either/or, not only/but also, and neither/nor. This avoids a run-on sentence that is often misread. It also prevents the confusion between phrases and clauses. This Grammarly webinar series on sentence structure provides more details about required sentence elements and varying sentence types.