Relative clauses: 多い人 vs 多くの人


I was practising a grammar pattern, so in my personal example I wrote:

[code]

    多いオーストラリア人
    
[/code]

However, a native speaker corrected me with:

[code]

    多くのオーストラリア人
    
[/code]

I understand that in relative clauses that adjectives go before the noun (e.g.
おいしい牛乳). How come they corrected me like this? How does this work? Or did I
learn relative clauses wrong?




多い is just a special case word, where, on its own modifying a noun, it takes
the form 多くの. However, it can take the 多い form attributively as part of a
longer relative clause such as オーストラリア人の多い場所 'a place where there are many
Australians'.

