The basic S V/C pattern can also be expanded by coordination. Whereas subordination ranks one element as more important than the other, coordination places elements on an equal footing. If the relationship of subordination is that of child to parent, the relationship of coordination is that of spouse to spouse. In a sentence it works like this:
The subject can be expanded by adding a coordinate element:
Lois and Esther type/letters.
And coordination can also be used to expand the complement.
Lois and Esther type/letters and memos.
Or the verb.
Lois and Esther type letters and memos but write-out short notes and signatures.
Now each element has been compounded with a resulting structure that might be represented as follows:
|Lois and Esther
|type/letters and memos
|write-out/short notes and signatures.
This sentence has a compound subject, a compound verb, and two compound complements. In every case the compound elements are coordinate to each other and therefore, because they are of equal importance, may be said to balance.
And just as we can subordinate either individual words or whole groups of words, the same is true of coordination. In the previous example we compounded the various parts of a single independent clause, but we could also coordinate two separate clauses.
Now our sentence has two independent clauses, each of which could stand alone as a complete sentence.