English does have a lot of loan words, but they are comparatively less frequently used than non-loan words. The overwhelming majority of the most commonly used core vocabulary is descended straight from Old English.
In fairness, there are some major counterexamples: “they”, “use”, and “people” are loan words in the core vocabulary.
"does" or at least do-support comes from celtic.
"have" is pretty close ot "avoir", and b/v (viz Ger "haben" is not a common sound correspondance.
"a" is not a word, it's a particle so short so that saying it descended is almost non-sensical. The proper form would be "an" (and even french "un" agrees).
"of", again a meaningless particle. There went so much wrong with prepositions, too, since PIE, they got turned up-side down, literally.
"non" rings of French, not German.
"to be" mostly changed since Germanic, and not straight forward either.
"than", nope, not original.
word has a fine root, most I'll take, core is not core vocabulary, the developed seemingly independently, but analogue to other Germanic languages, this, that are OK but close to Fr. ce, ca anyway, is is still pretty close to Latin est, Germanic or not ...
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