Kinds of

People have little trouble with expressions like "what kind of dog is that?".  But make "kind" plural and confusion reigns.

Singular: kind of dog

Plural: kinds of dog or kinds of dogs?

From what I've heard, people seem to prefer the latter, even though the former is logically correct.

Further confusion arises when "that" or "those" enters.  If people mean "We get many questions of that kind," they often try to invert the order and say something jumbled like "We get many of those kind of questions."