Can we go back to original Buddhism?

Finally, "Buddhism" makes verifiable sense!

THERAVADA Buddhism: Is this what the historical Buddha (Prince Siddhattha Gotama, "the Sage of the Sakas," the Shakyas, the Indo-Scythians) really taught? The Three Baskets (Ti-pitaka) of Suttas, Vinaya, and Abhidhamma (Discourses, Discipline, and Higher Doctrine). The Buddha did not speak Sanskrit, the exclusive liturgical language of Brahmin priests, but rather Magadhi (colloquial Pali, the lingua franca) and Prakrit. He certainly knew and understood Sanskrit, having been expert in it in past lives, a knower of the Three Vedas. The Pali canon is a collection of canonical texts preserved in the ancient Pali language the Buddha likely spoke.

• (Buddha's Wisdom) 

Why do monks and nuns chant in Pali?

The only reason Mahayana uses Sanskrit is because Brahmin (Brahminical Vedic Hindus) used it to whitewash Mahayana Buddhism into a kind of comprehensible form of Hinduism. The goal of Theravada, the "Teaching of the direct Elder enlightened disciples of the historical Buddha," is enlightenment here and now as soon as possible, whereas the goal of Mahayana is enlightenment never, only after an inexhaustible supply of living beings first attain it. When will that be? It will never be, alleviating the need for any Mahayana Buddhist to actually practice and bring what the Buddha taught about in one's own life. Imagining themselves supremely awakened buddhas of the future, there's never a need to do it now, the only time we actually ever have.

• What the Buddha Taught: revised and expanded edition with texts from suttas and the Dhammapada (Ven. Walpola Rahula, Paul Demieville)

Zen Buddhism came much later

(Tao Temple) We can't understand Zen until we understand this first