Phrases and Clauses
Phrases and clauses are the major units of sentence construction. Both are multi-word strings, but the nature of the words determines if that string is a phrase or a clause:
- A phrase is a group of words that work together but do not contain both a subject and a verb—e.g.,
- commercial off-the-shelf biosensors
- layer 2 of the ad hoc network
- after the fall of the Berlin Wall
- by performing a regression analysis on this second set of variables
- By contrast, a clause includes both a subject and a verb—a noun or noun phrase and the action it is performing (subjects are underlined, verbs are in italics):
- Chapter II describes the commercial off-the-shelf biosensors that form the basis of this research.
- Layer 2 of the ad hoc network contains the protocols used to transmit data between nodes.
- After the Berlin Wall fell,
- Bishop et al. isolated the effect of socioeconomic status by performing a regression analysis on this second set of variables.
Types of Clauses
Clauses themselves fall into two types—independent (main) and dependent (subordinate):
- Independent (main) clauses express a complete thought; they can stand on their own as sentences:
- Chapter II describes the commercial off-the-shelf biosensors that form the basis of this research.
To be complete, a sentence must contain at least one independent clause; a sentence without at least one independent clause is an incomplete sentence, also known as a sentence fragment.
- Dependent (subordinate) clauses are incomplete thoughts; they need—depend on—an independent clause to form a complete thought and therefore a complete sentence:
- After the Berlin Wall fell.
- Note the feeling of dissatisfaction this incomplete “sentence” creates: after the Berlin Wall fell . . . then what?
- After the Berlin Wall fell, Leonard Bernstein conducted a celebratory concert at the Berlin Schauspielhaus.
The defining feature of dependent clauses is their subordinating conjunctions, also known as “dependent marker words,” which are the words that lend dependent clauses their sense of incompleteness. There are numerous subordinating conjunctions, including “whereas,” “although,” “because,” “after,” and many others; you might recognize them as words often used to transition between thoughts. A list of subordinating conjunctions can be found in the links.
Finally, be aware that the boundaries between clauses are punctuated differently depending on what kinds of clauses a sentence contains and how the clauses are positioned in the sentence; for more information, see the pages on introductory commas, FANBOYS commas, and semicolons and colons.
Further Information on Phrases and Clauses
