Until quite late in History - until the Reformation in fact - all education was in the hands of the Church. The church's language was Latin, and Latin would be spoken in schools exclusively. So any educated person - almost, anybody who could write - would have a thorough grounding in that language. If a new word had to be invented, it was natural to them to adapt it from Latin roots.
The word latin in the English language would be Latin.
"He" is English is the personal pronoun is in Latin.
63% of English comes from Latin.
Latin: Pax English: Peace
"Tu" in Latin translates to "you" in English.
The verb est in Latin is "is" in English.
Testamentum in Latin is "testament" or "will" in English.
"Mind" in English is mens in Latin.
"Short" in English is brevis in Latin.
Quī in Latin means "what" or "which" or "who" in English.
M in Latin is "1,000" in English.
Infernus in Latin is "hellish" in English.