Is an adjective make uncountable noun countable?

Question

I've mentioned in the previous question a few days ago that advice is an uncountable noun. I've seen when the noun is attached with an adjective beside it, there are some that have article a and some don't

A question taken from an English grammar app verifies my question, but since it's an app, I'm still not sure. Anyway, this is the question and there are only 3 options:

My father gave me __ excellent advice.

1. a
2. the
3. an

The answer key is an. Why is it not the and why does it need an additional article when the verb advice is uncountable?

Answer 1

I would tell you that it actually sounds strange to say

My father gave me an excellent advice.

It is more natural (and idiomatic) to say any of the following:

My father gave me excellent advice.

My father gave me some excellent advice.

My father gave me a piece of excellent advice.

For the sake of argument, it is also possible to use "the". To do so, there must be some context such that there is one "advice" being discussed. One possible example:

A: Wow, turning it around is a great idea! How did you figure that out?

B: My father gave me the excellent advice, and I took it!

Answer 2

You are right that "advice" is uncountable, and the app question seems odd.

Many nouns can have both countable and uncountable senses. However "advice" is nearly always uncountable.

In the context in the question, you could either use no article "gave me excellent advice". Or you could use a determiner "some excellent advice". Or a quantifier "a piece of excellent advice" or perhaps "an excellent piece of advice".