Final answer:
The sentence that correctly uses phrases and clauses is 'Of course, he was the greatest president since Lincoln.' The sentence is punctuated correctly and forms a complete thought with a properly identified subject and verb.
Step-by-step explanation:
The sentence that correctly uses phrases and clauses is: Of course, he was the greatest president since Lincoln. This sentence includes a main clause with the subject and verb "he was" and uses a comma after the introductory phrase "Of course," which improves the readability and clarity of the statement. The two other options provided are either incomplete sentences (like "The greatest president since Lincoln" which lacks a main clause altogether) or improperly punctuated (as in "They said, he was the greatest president since Lincoln," which incorrectly separates a main clause with a comma when it should be followed by either no punctuation or a coordinating conjunction).
The importance of correct punctuation and the identification of proper subjects in sentences is emphasized, as in the example of subject/verb agreement: The play [with such true witticisms and parables] comes highly recommended. This sentence correctly identifies "play" as the subject, not the intervening prepositional phrase, and uses the singular verb form "comes" to match it.