In the frame of a long hafted weapon, what would be most common for a simple farmer to have? would they have a long hafted bill hook, or more likely have a spear or boar spear?
thanks!
Broadly speaking that primarily depends on the time period.
Spears were really ubiquitous among infantrymen and thus the peasantry until the beginning of the 13th century to the point most adult men of an age to be levied would own one and in many places would be legally required to. A specific boar spear might not be as common in many places where boar hunting would be legally restricted to land owning nobility with doing so being poaching for the average villein.
But over the course of the 13th century you really get a massive branching out in the kinds of polearms being used with spears falling to the way side. What exactly that polearm is varies massively. Billhooks as a tool had already been common for centuries particularly in the British isle but it was in the mid 1200s that we start to see the military variant with firstly a long shaft and over time a evolution of the head to include a variety of features. While the bill hook wasn't exclusively used here the bill hook was most popular in England. As i said the head developed over time and at the very end of the medieval period this more developed version sees increased use in Italy and going into the renaissance and on occasion elsewhere.