By requiring the translation of natural language sentences into standard-form categorical claims, the clarifying work of categorical logic begins before any inferences occur. For purposes of categorical reasoning, they all get the job done equally well. Of course, if we know for certain that we are referring to all members of a class, a universal claim would be the appropriate expression to use. There are some natural language sentences that look pretty much like standard-form categorical claims. No factories are vegetables.
Some businesses are corporations.
Some corporations are not businesses. Sentences like these readily translate into standard-form categorical claims, but they are by no means the only kinds of sentences we can work with in the operations of categorical logic. Before we get any further into translating natural language sentences into standard-form categorical claims, a few more points need to be brought into the discussion. First, the subject and predicate terms of a standard-form categorical proposition always designate classes, but those terms may be complicated expressions rather than single words. The important point about this is to recognize that whether a class of things or actions is easily named with a single word or requires a paragraph-like specification, it is still one kind of thing or action that we happen to be talking about.