Level I Diagrams
A simple Kellogg-Reed diagram begins with two lines. Draw a long horizontal line. It's on this line that you will write your subject and predicate. At the center of the diagram, draw a vertical line. Notice that the line is shorter on the bottom. To help you visualize things, we'll color-code our diagrams. The subject of the sentence will be blue, and the predicate will be green. Don't know how to identify subjects and predicates? Please go back and start here.
Simple subject and predicate
If you have a sentence with only a simple subject and predicate, the Kellogg-Reed diagram is actually very simple. Just write the subject on the left side of the line and the predicate on the right. The sentence "Kelly laughed" is diagrammed as:
No matter what you are diagramming, you always begin by placing the subject and predicate. If I give you a longer sentence (like "You always begin by placing the subject and predicate") and ask you for a simple subject/predicate diagram, you'd write them out like so:
Sometimes we don't actually write or speak the subject of the sentence. It's implied. When your mother looks at you and says, "Call before you leave," you know that she means "You call before you leave." To diagram an implied subject, we pretend like it IS written in the sentence. As an example, take the sentence "Behave!"
What if there is more than one subject of your sentence? How would you diagram "John and Sarah ran" or "John, Sarah, and Susan ran," since each of these sentences has multiple subjects?
To make a compound subject diagram, we modify the left side to give us two baselines. Notice the dotted line that connects the two baselines. You can then write your subjects on the baselines:
Finish out the diagram by writing your predicate in the appropriate spot. Add the conjunction joining your subjects on the dotted line.
To add an additional subject, just add another baseline on the left.
If you have more than three subjects, consider rewording your sentence! :)
Compound predicates are handled in the same manner as compound subjects--just on the other side of the line! Look at these two examples: John ran and jumped. John ran, jumped, and fell.
Multiple/Compound subjects and predicates
Compound subjects and compound predicates may seem complicated, but all we're really doing is joining what we've learned above. For example: John and Sarah ran and jumped.
Think you understand? Then move on to the Level II diagrams.