Pirates probably talked like normal sailors! Words like “arr” and “matey” and phrases like “walk the plank” and “shiver me timbers,” are pure pop culture creations.
English-speaking pirates of the 17th and 18th centuries probably just spoke, well, English (or more specifically, 17th-18th century English). It is believed that they spoke just like English-speaking merchant sailors of the time.
What we know as “pirate-talk” was just another one of Disney’s creations. Many of the phrases that you’ve associated with pirates your entire life, can be traced back to the 1950s Disney movie Treasure Island, starring Robert Newton as fictional pirate Long John Silver. Newton’s performance was chock full of “arrs” and “shiver me timbers.”
Not only did people love it, but they took it to be true. The punishment of “walking down the plank” is also something that there are no records of pirates doing. Again, it’s all Hollywood. Talk about movie magic.