Read Lecture Notes: The Main Line

Every sentence has a main clause. It may have a lot of other things too, but it always has a main clause. The main clause answers the question, WHO DID WHAT?

Each of these sentences consists of one main clause.

• The bear slept.
• Linda kicked a ball.
• Persimmons give me a bellyache.
• That cake smells delicious.
• Terence called Rosaria a genius.

In sentence diagramming, the main clause is represented on the main line. In each of these diagrams, there is only a main line, with nothing (except one article per sentence) branching from the line.The five patterns represented in these five diagrams are the only possible clause patterns in the English language. We will look much more closely at these patterns in Lesson 5 of this module.

The five patterns represented in these five diagrams are the only possible clause patterns in the English language. We will look much more closely at these patterns in Lesson 5 of this module.

Many (if not most) sentences you write will be considerably more complicated than the sample sentences above. The diagrams for those sentences will have lines sprouting off the main line and branching in different directions, as in this sentence:

Unconcerned by the raucous activity just outside his cave, the bear slept like a baby.

Everything that branches off the main line is a modifier. Modifiers include (but are not limited to) adjectives, adverbs, prepositional phrases, participles, infinitives, and adverbial and adjectival clauses.

Adverbial modifiers answer questions about the action:

• How?
• When? 
• Where? 
• Why?

Adjectival modifiers answer questions about nouns:

• What kind?
• Which one?
• How many?

This module of the course is all about the main line—the main clause, that main question: WHO DID WHAT? Most of the rest of the course is about everything that branches off the main line.

Skills to work on in this lesson are identifying that main line and SEPARATING it from all the modifiers.

Consider this sentence:

The raccoon rattled the trashcan.

This is a straightforward clause with a subject (raccoon), a verb (rattled), and a direct object (trashcan). Who did what to whom? The raccoon rattled the trashcan. Here’s the diagram:

Now, consider this sentence:

The raccoon that I was telling you about, with the missing ear and the unusually bushy tail, rattled the trashcan behind my garage with an insistence that bordered on obsession.

If we were to diagram this sentence, it would look like this:

Compared to the first raccoon sentence, this one is impressively complicated. But perhaps the most impressive thing about these two diagrams is the realization that the main line is exactly the same.

Who did what? The racoon rattled the trashcan. This is true for the first, simple raccoon sentence, and it is true for the second, complicated raccoon sentence. The main line is five words (if you count the two the’s). In the second sentence, the other 25 words sprouting off the main line are all modifiers. They tell us which raccoon. They tell which trashcan. Notice also that some parts of the modifiers have their own modifiers.

Once you get off the main line, language allows for infinite complexity. But on the main line, the options are NOT infinite. In fact, there are only five patterns, and they are easy to memorize, and with a little practice, you can get good at recognizing them.