All Romance languages descend from a Latin parent, and many words based on Latin are found in other modern languages such as English. Romance languages are not derived from Classical Latin but rather from Vulgar (or spoken) Latin. Latin was the lingua franca during period making it the learned language for scientific and political affairs, for more than a thousand years, being eventually replaced by French in the 18th century and English in the late 19th century.
Latin and the SCA
Many people in the SCA have Latin mottos but there are very few people who understand Latin well enough to give good advice on translations or interpretations. This has lead to a small number of mottos where the perceived meaning and the 'true' meaning are not identical (its like the result of game of chinese whispers) and other cases where the grammar used makes the motto totally wrong (literal translations done by people using Latin dictionaries suffer this problem and tend to make Latin speakers giggle).
- "For the translator ought to have the knowledge of the subject which he translates as well as of the two languages, the one from which and the one into which he is translating. ... Others who did a lot of translating into Latin such as Gerard of Cremona, Michael Scot, Alfredus Anglicus, Hermannus Alemannus and the translator of Manfred ... had the arrogance to translate innumerable writings but they knew neither the sciences nor the languages, not even Latin and in many places they inserted words of their own mother tongues."
Latin and English
English grammar is not a direct derivative of Latin grammar. Attempts to make English grammar fit Latin rules -- such as the contrived prohibition against the split infinitive -- have not worked successfully in regular usage. However, as many as half the words in English come to us through Latin, including many words of Greek origin, not to mention the thousands of French, Spanish, and Italian words of Latin origin that have also enriched English.