Many words, but definitely not all.
Although considered a Germanic language, English contains many Greek, Latin, and French words. In fact, it contains more Greek words and word roots than immediately recognized because they came to English via Latin or Old French. Via isn’t one of them; that’s straight Latin meaning way or street, as in the Via Appia. The first documented use of via in English is in 1615 by one Helkiah Crooke, a British physician, using it to mean “by way of.”
In my day, Latin was required in high school. A century or 2 ago, scholars couldn’t lay claim to that “title” without a reading knowledge of Ancient Greek and Latin. If we had a fraction of that background, we could easily pick out philosophy and alphabet (Alpha, Beta) as Greek and genus and virus as Latin. We also have direct Latin usage in pro bono, habeas corpus, and that so useful, et al. (and others; the al. is the abbreviation for alia, the Latin neuter, plural for others).
Direct Greek words often have minor spelling changes in American English, but retain the digraph in British and scientific English, such as orthopedic/orthopaedic. Digraphs are 2 letters expressed as one sound. The word digraph, itself, is from Greek; di=2, graph=written. Consonant digraphs include ch, sh, ng. Vowel digraphs include ai, oe, au. Digraphs are more common in British usage then American English. Phenomenon and anthropology are other direct descendants.
If you try to determine what percentage of our words come from any of those aforementioned languages, you’ll find numbers as diverse as those languages themselves! Needless to say, however, with some digging you’ll find a great number from Greek, even if filtered through other Ancient and later languages.
Let’s get back to Greek. Take the word democracy: demos = people and kratos = power. Not only does the word come from the Greek, but so does the concept. Could it be any clearer? The people have the power, which can easily be understood as 1 citizen = 1 vote. Citizen, on the other hand, goes back via Norman French to Old French, citizain, to Latin, civitas = city. Other Greek derived words and their concepts include philosophy, drama, and tragedy.
Ancient Greek is considered one of the oldest “true” Indo-European language because it consisted of both vowels and consonants. Note the use of alpha/beta = alphabet (vowel/consonant) above. Modern Greek is probably derived from Koine, a commonly spoken Ancient Greek dialect. Modern Greek is the official language of Greece today.
Here are a few more examples of English words derived from Greek. There actually are thousands.
- Dinosaur: deinos=terrible + savra=lizard.
- Acrobat: akri=tip, edge + vaino=walk
- Schizophrenia: schizein=split + phren=mind
- Cemetary: koiman=to sleep, koimenterion=dormitory
There are also a number of English words based on Greek mythology. Here are a couple of those.
- Europe: Europa was the exceptionally beautiful daughter of a Phoenician king that was abducted and seduced by Zeus, camouflaged as a white bull (that image now on the 2€), and became his lover. It was first used as a geographic term in the Homeric Hymn to Delian Apollo referring to the western shore of the Aegean. Starting at least in the 6th C BCE, it was used as a geographic term.
- Mentor: He was the close, trusted friend of Odysseus who stayed behind to watch over Telemachus, Odysseus and Penelope’s son, while Odysseus went to fight in the Trojan war, a task he was loath to do, even before he knew of or experienced his 10-year odyssey of treachery on his journey home.
- Echo: She was a nymph with a magnificent voice and witty conversation, whom Zeus fell in love with. Hera, his wife, suspected Echo of being one of his conquests, and cursed her to only be able to repeat what she heard from others.