Sentence Structure
In fourth grade, we focus on three types of
sentences: simple, compound, and complex.
1. Simple sentence
Every sentence has two parts: a subject and a predicate
A sentence expresses a complete thought.
Example: The dog ran quickly.
subject
predicate(verb)
subject
predicate(verb)
The subject can be compound: The boys and the girls arrived early.
The predicate (verb) can be compound. The boys raked and cleaned the
yard.
subject
predicate (verb)
2. Compound sentence
Two complete sentences joined with comma + a conjunction (FANBOYS:
For, And, Nor, But, Or, Yet, So) In fourth grade, we will focus on four of
these: SOBA (so, or, but, and).
Example:
Comma then conjunction
Sentence 1
sentence 2
The dog ran quickly, and then it stopped suddenly.
Notice the pattern of this sentence above:
Sentence, conjunction sentence.
Note the punctuation and capitalization of the above sentence.
To understand the third type of sentence, you must understand the
difference between phrases and clauses.
If a group of words contains both a subject and a verb, that group of words
is a clause.
If the group of words does not have both a subject and a verb, that group of
words is a phrase.
We threw the ball.
Because this group contains both a subject and a verb, this group of words
is a clause.
subject verb
Against the wall
Because this group does not contain both a subject and a verb, this group
of words is a phrase.
There are two types of clauses: independent and dependent
Independent clauses can stand alone as sentence. Another name for a
single independent clause is a simple sentence.
When two independent clauses (or simple sentences) are joined together
with a comma and a conjunction, a compound sentence is created.
3. Complex sentences
Although a dependent clause contains both a subject and a verb, it cannot
stand alone as a sentence because it does not express a complete
thought. It is dependent on something else to make a complete thought. It
needs to be joined with an independent clause. When this happens, a
complex sentence is created.
Example: After we go to lunch
subject
verb
What will happen after we go to lunch? This is not a complete thought.
Notice the subject and the verb. Also notice that this clause starts with a
special type of conjunction called a subordinating conjunction. (Not any of
the FANBOYS). There is a large list of subordinating conjunctions, but in
Fourth grade we will focus on a few of these:
AAAWWUBBIS- After,Although,As,When,While,Until,Before,Because, If, Since
To make a complete thought, a dependent clause must be attached to an
independent clause.
After we go to lunch, we go to recess.
subordinating
conjunction
subject
verb
subject verb
Remember dependent clauses start with subordinating conjunctions:
(AAAWWUBBIS) After,Although,As,When,While,Until,Before,Because, If, Since
The dependent clause can be at the beginning of the sentence or
at the end.
When an AAAWWUBBIS is at the beginning of a sentence, it must
be followed by a comma. When it is at the end of the sentence,
no comma is needed.
Examples: While it was raining, I stayed indoors.
I stayed indoors while it was raining.
When you see AAAWWUBBIS words, look for a dependent clause.
Application:
To add variety to your sentences when writing, try starting a few
of your sentences with an AAAWWBBUIS clause.
Be careful not to confuse a prepositional phrase for a dependent clause.
After lunch we will go to recess.
This sentence begins with one of the AAAWWUBBIS words, but “after lunch” does
not contain a subject and a verb. With no subject and verb, this group of words is
a prepositional phrase.