Dictionaries have 「たくさん」 listed as being either a noun or 形容動詞。Googling "たくさんな" returns only 190,000 hits; none of the top 20 pages are professional websites. Rather, they are only blogs.
My impression is that, practically speaking, 「たくさん」 is used only as a noun? For some idiosyncratic reason, it's also listed as 形容動詞? Can anyone shed some light as to what's going on? Is this issue related to the meaning of 形容動詞、or just about that the word, 「たくさん」, is exceptional。?
thanks.
My impression is that, practically speaking, 「たくさん」 is used only as a noun?
Unless you belong to the school who believes that 形容動詞 are really nouns, I don't think it's a noun, e.g. you cannot say *たくさんを食べる. And I don't see any examples in the goo dictionary that suggest it's more of a noun than any other 形容動詞.
Is this issue related to the meaning of 形容動詞、or just about that the word, 「たくさん」, is exceptional?
I don't see anything exceptional about it. Some 形容動詞 use な, some use の. This one usually uses の, like e.g. 普通.
I'm not sure why the goo dictionary doesn't list たくさん as an adverb, although it lists examples of adverbial use. This is quite common for 形容動詞 of quantity and classifiers to be used adverbially
少しのご飯を食べる ～ ご飯を少し食べる
３杯のご飯を食べる ～ ご飯を３杯食べる
I cannot present a linguist's arguement on this but surely たくさん can be regarded as both grammatically and in meaning as equivalent to "plenty": It is a noun describing a state （数や量が大きい様子）which can also be used as a counter representing an unspecified amount:
There is plenty of N = Nがたくさんあります。
cf: We have two N. = Nが 二つあります
