As for grammar, those who work through the writings of Thomas Jefferson, who had a classical education, or George Washington, who did not, or their English contemporaries Samuel Johnson, Edward Gibbon and Edmund Burke, will find that the syntax of Greek and Latin had affected the complexity and clarity of their expression and so of their thought. We need to know Latin if we want to think like the Founders.
Forrest MacDonald saw this clearly. "In thinking in eighteenth-century English...a rudimentary knowledge of Latin is highly useful; after all, every educated Englishman and American knew Latin, English words were generally closer in meaning to their Latin originals than they are today, and sometimes, as with the use of the subjunctive, it is apparent that an author is accustomed to formulating his thoughts in Latin."-- E. Christian Kopff, Open Shutters on the Past: Rome and the Founders in Vital Remnants: America's Founding and the Western Tradition (ed. by Gary L. Gregg II, ISI: 1999), pg. 74.