Vertex ... Vertices

The use of the singular or plural of the word VERTEX is a common problem around my industry. We deal with vertices all the time when creating and manipulating GIS products. 

I understand that the English language rule is a little obtuse, but it really is quite simple. One vertex: VERTEX. More than one vertex: VERTICES.

It really grates my last nerve when I hear it's misuse in technical conversation as often as I do. Colleagues and non-colleagues alike use the plural form without the 's' when they intend to use the singular form.  What's more, it is actually acceptable to say VERTEXES for the plural form - which should simplify the matter, but most do not choose to take that opportunity.

I can excuse the misuse if it is occasional, but it happens all the time. 

ALL THE TIME