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The rules of English grammar are best understood if you understand the underlying structure of the language. In this presentation, we will explore the make up of a small, but important unit of the language: the sentence.
What is a sentence?
Phrases and Clauses
What is a sentence?
To communicate an idea
What the sentence is about
At the most basic level, a noun or pronoun
added methanol to the solution.
was added to the solution.
Add methanol to the solution. (
The subject, simply, is what the sentence is about. At the most basic level, it can be just a noun or a pronoun, but it can be more complicated. In these similarly structured examples, there are three different subjects.
Describes what the subject is or does
At the most basic level, a verb
added methanol to the solution
Add methanol to the solution
The predicate is a modifier. It gives details about what the subject is or does. At the most basic level, it can be just a verb, but usually it gives a lot more detail about the subject. In these examples, everything except for the subject is considered the predicate.
Part of the predicate
What the subject is acting upon
Direct objects and indirect objects
Objects are part of the predicate and are what the subject is acting upon. Objects can get fairly complicated, with direct objects and indirect objects only scratching the surface of their complexity, but we will not discuss them much further because they do not really impact we construct sentences.
Indicates where to pause in writing
Most sentences end in periods
The third part of a sentence is the punctuation. We use punctuation to indicate pauses in our writing, and to signify when a sentence is finished. See the GradWRITE presentation on “Punctuation” for a complete look at common issues with punctuation.
Phrases and Clauses
Groups of words that are not quite sentences
Now that we know the basic components of a sentence, we can see how we build them. Phrases and clauses are groups of words that are not quite sentences on their own. They need help to form complete sentences.
Word clusters without a subject-predicate pair
Provide more information than simple subjects and
Cannot stand on own
Noun phrase: The guitarist’s performance...
Verb phrase: ... seems to be starting.
Phrases are groups of words that do not have a subject-predicate pair; that is, they are missing either one component or the other. Because they use more words, they can give more
information than simple subjects and predicates but cannot stand on their own as sentences. In the examples, the noun phrase is missing a predicate to complete it, and the verb phrase needs a subject.
Contain a subject and a predicate
Can stand alone as a sentence
She added methanol to the solution.
Cannot stand alone as a sentence
Needs an independent clause to complete it
Acts as a noun, adjective or adverb
After she added methanol to the solution
, she stirred
Dependent clauses are a little tricky. They do have complete subject-predicate pairs, but they also have at least one other word in them that means they cannot stand on their own. They need to be joined with an independent clause in order to be a part of a complete sentence. Dependent clauses can act as nouns, adjectives or adverbs within a sentence. In this example, the word “after” makes the first clause dependent, meaning that we need a second clause to complete the sentence.
Expresses an idea using a subject and a predicate
Simple, Compound, Complex, Compound-Complex
Not just about length
We’ve been using the definition of sentence as a group of words that express an idea using a subject and predicate. In practice, there are four kinds of sentences. The differences have very little to do with length and much more with what kind of clauses are used.
One subject-predicate pair
Methanol was added to the solution.
Two or more independent clauses in one sentence
Methanol was added methanol to the solution;
she stirred the beaker.
Methanol was added to the solution; this
caused a reaction.
Methanol was added to the solution;
subsequently, a reaction occured.
FANBOYS: For, And, Nor, But, Or, Yet, So
Methanol was added to the solution, and this caused
The second method of joining independent clauses into compound sentences uses short transition words called co-ordinating conjunctions. The acronym FANBOYS incorporates the first letter of all seven of these important little words. To punctuate properly, simply separate the two clauses with a comma, add the appropriate conjunction and you’re good to go.
1 independent clause and 1+ dependent clauses
After adding methanol to the solution, the beaker
Methanol was added to the solution, while the
beaker was stirred.
Complex sentences have one independent clause and at least one dependent clause. As we’ve seen before, dependent clause needs the independent clause to complete the sentence. From the examples, we can see that the dependent clause can come either before or after the independent clause.
2+ independent clauses and 1+ dependent clauses
While methanol is added to the solution, the beaker
is stirred, and the colour will change.
Compound-complex sentence are a mix of compound and complex sentences. They have at least two independent clauses (compound) and at least one dependent clause (complex). Compound-complex sentences are not used often, mostly because they tend to be rather complicated.
Think about the effect you want
Short simple sentences attract attention
Compound sentences invite comparison
Compound-complex sentences give lots of information
When writing, it is important to think about the types of sentences you are using. A large text should have a healthy mix, but you need to think about the different effects of each type. For example, short simple sentence will attract the readers attention because they are so short. Using a compound sentence allows you to compare elements in the different clause. A complex sentence can show how the element in the dependent clause relies on the independent clause and compound-complex sentence can communicate a lot of information.