An interesting post I read recently about 「多い」 and 「少ない」 got me thinking (probably a bit too much). The post is also all in Japanese, so it’s good reading practice as well.
As Minako Okamoto points out, you can’t directly modify a noun with 「多い」 and 「少ない」 in the manner below.
I believe this is due to the idiosyncrasy of having adjectives that indicate multiple objects in a language that has no singular/plural distinction. (I have another post that explores this theme in depth that has been in my draft folder forever.) In addition, other words that indicates multiple objects such as 「少数」 and 「多数」 are almost always used as nouns despite the fact that they are descriptive and would normally be thought of as adjectives. (I have no idea whether they are officially classified as just nouns or as both nouns and na-adjectives.)
The easy way
There are many ways to get around this problem of not being able to directly modify the noun with adjectives indicating amounts. For instance, you can make the adjective a predicate or use adverbs such as 「たくさん」 and 「少し」 instead as Minako demonstrates.
The not-as-easy way
While this works fine for elementary Japanese, more complicated sentences might call for a direct noun modification. This is especially the case when the main focus of the sentence is something else and the fact that it’s numerous or few in number is extraneous information. In order to do this, all you have to do is modify as a noun using 「の」 instead of the traditional adjective-noun modification. For i-adjectives, you have to convert it to an adverb first by replacing 「い」 with 「く」.
(I completely made this example up so I have no idea if this is true and I would guess probably not.)
Oddly enough, I have never seen the opposite 「少なくの」. I guess every language has its quirks. You can however, use 「少数の」 instead.
KISS (Keep it simple, stupid!)
Some people might look down on what I called “elementary” earlier but in languages, simpler is always better. So in most cases and especially in conversational Japanese, you should just stick to the simpler method of using words like 「たくさん」 and 「少し」 without mucking around with what is more of a formal written style using 「多くの」, etc.
I should also note that there is a big difference between a direct noun modification and a subordinate clause modification as the two examples below show.
Unlike the first sentence where 「多い」 is directly modifying 「レストラン」, the second sentence is perfectly fine because 「多い」 is the predicate in the clause 「レストランが多い」 and is not directly modifying the noun 「東京」 by itself.
So in most cases, if you stick to the basics, there should be no problem at all. In fact, I have personally never noticed this peculiar problem until I consciously thought about it. In conclusion, remember that “brevity is the soul of wit”!
Can anybody think of any other adjectives that have similar issues?