grammatical-number
What's the plural of "chewing gum"?
Hearing "do you have any chewing gums?" sounds wrong; I would say "do you have any chewing gum?", but looking it up, there seems to be a bit of confusion on Google. Some results indicate that "chewing gums" is the plural form of "chewing gum", while others say that "chewing gum" is an uncountable noun, and has the same plural as the singlar form.
Is kind of patents ever correct?
It’s a bit informal. Kind of (plural noun) is surprisingly uncommon in formal writing, fairly uncommon even in journalism, but common in speech and fiction:
She had the kind of eyes that followed you around the room. I’d thought that happened only with paintings… (fiction)
But I don't think it faces the kind of problems, say, a Los Angeles does. (spoken)
Those kind of games tend to be tiebreakers with teams that are alike. (spoken)
Does kind of patents take a singular or plural verb?
Plural, almost always. This is like how a lot of people is plural. No one says A lot of people is upset about it. So it’s what kind of patents are, not is.
Is this the kind of thing where whatever option I choose, it’s going to sound wrong to someone?
Yes.
Then is it best to just recast the sentence entirely?
That’s up to you. I probably would, unless the context was informal.
Well, this is an example of why Google NGrams isn't a precise indicator. When we compare the two directly, aircrafts simply can't get off the ground:
Now, this result is also flawed since it is impossible to separate uses of aircraft (singular) and aircraft (plural). It is also impossible to factor out typos (aircrafts vs. aircraft's) and so on.
The point is, don't read too much into what an NGram shows (or at least take the graphs with a grain of salt), because a great deal of the time what you wind up with is this sort of thing:
(BTW, the huge spike in the use of aircraft in the early '40s is almost certainly due to the air war in Europe and the Pacific.)
Best Answer
Chewing gum is an uncountable (mass) noun, and therefore follows these rules for plurals:
singular: chewing gum This chewing gum is delicious.
plural 1: chewing gum Do you have any chewing gum?
plural 2: chewing gums Ten of the chewing gums in our test lost flavor after two minutes.