I was taught as a youngster (pre-PC days) that Squanto spoke English because he had been captured and sold into slavery, eventually obtaining his freedom and returning to Massachusetts.
Squanto’s tribe had disappeared and he was held captive by other suspicious natives. He was so willing to help the Pilgrims because they treated him better.
And guess who helped Squanto gain freedom from the slavers?
Christian monks!
The sad thing was his whole village perished to disease brought over from Europe.
It was in Plymouth Harbor, Massachusetts. When the Pilgrims got there, the fields were there—a little overgrown, but no trees—the remains of wigwams somewhat stood, and all the inhabitants gone. The few survivors had gone to live with other tribes.
Had Squanto not been captured, he may well have died in the epidemic.
In 1620? I think you might have your timelines screwed up a little.