The volcanic neck is formed when lava solidifies inside the volcano. just the same way clay or cement solidifies inside a mold.
When the large external surface of the volcano erodes away, the volcanic neck will be left standing because it is a harder rock that the volcanic body. This can be seen as the "intrusive igneous magma" that is left behind after the surface is removed
There is a large period of time in which the French and Portuguese colonized Africa. The natives took on those languages, which influenced the culture.
