more or less, it’s the root of what became English. There are a lot of words with direct overlaps, like house, wife, or hound, but have different spellings and pronunciations. But then there are a lot of words that are completely foreign to English speakers, like Beornwiga (a warrior hero), Fefitehwearf (to my understanding, a group of people on foot), or Eaxlgestealla (like “comrade”).