- What kind of car are you interested in?
- What kind of cars are you interested in?
- What kinds of cars are you interested in?
Is there any one that can’t be allowed to be said?
I would think that #1 could be possible, when the speakers, intending to buy a car, are in a shop which sells cars. And in #2, when it’s not the case as 1, plural cars are more reasonable, in my eye. In 3, for ‘cars’ is plural, it seems that plural ‘kinds’ can be used - but sounds somewhat strange. Can all three be said or not?