ADJECTIVES BEFORE A NOUN
When two or more adjectives come before a noun, and are not connected by a conjunction, the meaning to be conveyed determines the punctuation:
75. This is a large wild grape.
75-1. This is a large, wild grape.
The punctuation is correct in each of the above sentences; but the two sentences do not mean the same.
Sentence No. 75 says that the grape is a large one in the class of wild grapes, confining the comparison to wild grapes.
Sentence No. 75-1 says that the grape is large and is wild. It is large in comparison with all kinds of grapes.
In No. 75 we give the language its natural meaning. In No. 75-1 we use a comma to show that the natural meaning is not the meaning we wish to convey; we disconnect “large” from “wild grape,” as, in Sentence 1-1, we disconnected words standing in an apparent relation which was not the real relation.
Other examples at the end of this chapter will further illustrate the punctuation.