Question

what kind of a person is he?

Answer 1

1、what kind of后接不可数名词，可数名词单数；可数名词复数也有，但很不普通。回答可有一种或多种。
What kind of water is safe to drink?哪种水可以安全饮用？

What kind of fruit(s) do you like? --The apple./Apples./The apple and the orange./Apples and oranges.你喜欢哪种水果？—苹果/苹果或者橘子。

2、what kinds of后接不可数名词，可数名词的单数或复数。回答可有一种或多种。
What kinds of water yield fastest plant growth?

--What kinds of fruit(s) do you like? --The apple./Apples./The apple and the orange./Apples and oranges.

3、what kind of后亦可接a/an，但此时无关种类，而意为“什么样的”。
--What kind of a person is he? --He is good-natured.

提醒——
1、what kind of也好，what kinds of也好，语法中心是kind或kinds；至于of，则引出不可数名词，可数名词的单数或复数，构成介词片语，做kind或kinds的后置修饰语。

2、两种情况的询问，都可回答一种或多种，因为问话的人不可能预知到对方回答几种。