What is the meaning of S-LV pattern?

Sentences in English often follow predictable patterns. One such pattern involves a subject (S) and an LV (linking verb). The subject is the person or place or thing performing the main action. The linking verb does not show action (as verbs usually do): this type of verb simply re-name or describe the subject. Here are a few of the most common examples of an LV: am, are, is, was, were, be, being, been. Sometimes, the Words "feel" and "seem" are also used as linking verbs.

Some examples: (Notice the S and then the LV, which can then be followed by an adjective or a prepositional phrase, or whatever else is in the rest of the sentence.) (1) John is intelligent. (2) Abraham Lincoln was president during the civil war. (3) The final exam seems really difficult. (4) I am happy to help you.