These kind of....vs This kind of...
I read this on Duolingo:
"If you are saying mushroom in the plural mushrooms then you must use "these"
"these mushrooms" vs "this mushroom"
So it becomes "these kind of mushrooms" or "this kind of mushroom".
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Are you agree with that explanation? If it's so why I should use "these" in plural, It seems to me this word refers to the word "kind" (singular).

What do you think about the question: "What kind of mushrooms are on the table?" Is this correct?

Question

These kind of....vs This kind of...
I read this on Duolingo:
"If you are saying mushroom in the plural mushrooms then you must use "these"
"these mushrooms" vs "this mushroom"
So it becomes "these kind of mushrooms" or "this kind of mushroom".
-----
Are you agree with that explanation? If it's so why I should use "these" in plural, It seems to me this word refers to the word "kind" (singular).

What do you think about the question: "What kind of mushrooms are on the table?" Is this correct?

Answer

You are correct - there is only one kind, so it should be this kind of mushroom.

What kind of mushrooms are on the table, or what kind of mushrooms are these? is correct if you see only one kind.  If there were different kinds of mushrooms then you would ask 'what kinds of mushrooms are these'?

Answer

I agree with Hilary.  "This" is a singular adjective. "These" is a plural adjective.

The word "kind" refers to a category or group of at least two things.

So, if you are talking about related things, e.g. fast cars, and you want to include a reference to all similar cars, then you could say "... this kind of car".