It is too narrow an approach to ...

[atabitaraf]

I see it a lot that in some writings, adjectives precede articles as follows.

1. It is too narrow an approach to ...
2. I bough so beautiful a T-shirt that ...
3. It is much better a way to talk now ...

I couldn't find the rule about it. When can I use it?

 

[probus]

It is highly unlikely you saw 2 and 3, because they are unnatural.

2. I bought such a beautiful ...
3. It is a much better way to ...

There isn't a rule as such, but whenever "too" modifies an adjective the article follows the adjective.

They sold me a too big hat. (Incorrect)
They sold me too big a hat. (Correct)

 

[atabitaraf]

It is highly unlikely you saw 2 and 3, because they are unnatural.

2. I bought such a beautiful ...
3. It is a much better way to ...

There isn't a rule as such, but whenever "too" modifies an adjective the article follows the adjective.

They sold me a too big hat. (Incorrect)
They sold me too big a hat. (Correct)

So, it is only about 'too', not 'so' or 'such'. Am I right?

 

[probus]

See my example 2 above for such, which works the same as too with respect to the indefinite article..

So, on the other hand, is an adverb rather than an adjective like such. In these contexts too is also an adverb.

 

[atabitaraf]

See my example 2 above for such, which works the same as too with respect to the indefinite article..

So, on the other hand, is an adverb rather than an adjective like such. In these contexts too is also an adverb.

In our example, 'too' is used in this way: too + adjective + article + noun (too narrow an approach).
The above structure might not be used for 'so' or 'such', as I learned it from your previous comment.