They obviously had no common language or even gestures. How were they able to communicate?
hi! this is a hugely popular question in this sub; check out this FAQ section for previous discussions, particular the subsection How did colonialists talk with indigenous people?
It's an interesting question that I don't know how to fully answer & I hope somebody will expound upon this. However, I can shed a little light. Remember that Columbus was planning to go to Asia. As a result, he brought an interpreter- Luis de Torres on the first voyage who could speak Hebrew and Arabic, two common languages of commerce. I'm not sure how Columbus or other explorers communicated on future voyages, though I hope somebody else delivers.
Once Europeans started colonizing the New World, it was a common practice to release young children to the local Native Americans so that they could learn the language and serve as interpreters. Similarly, Native Americans would spend some time in settlements to learn European languages (most famously Pocahontas).