Using 〜になる instead of です?

Question

I've been trying to figure out why a native speaker told me to use 〜になる instead of です here.

My original sentence:

日本語のテレビ番組を見るのは良い練習です。

Corrected sentence:

日本語のテレビ番組を見るのは良い練習になります。

I've asked them about the reason why, and all they said is that 〜になる is more natural to use, even though です is still technically correct.

But, I don't understand why it is more natural to use 〜になる here. I was always taught that the 〜になる construction meant "to become" or something along those lines. And I can't find anything about it online, unless I'm just looking in the wrong places?

Answer 1

I'm not a native speaker, but here's my gut feeling.

練習 is a process (something that grows/changes with time) that you continue to do. です has a static feel about. 私は先生です --> That's what I am: a teacher, it doesn't change. But 練習 is something that changes and develops with time and so needs a verb to match the feeling of change. And, that verb would be なる.

Also, になる has something of a future feel about it as in, "If I watch Japanese tv, it will be good practice". When you're saying 日本語のテレビ番組を見る you're not really talking about what you're doing in the moment right now. It's something you intend to do. As such there's a certain vagueness to it which feels more suitably expressed with になる instead of です, which has a much stronger sense of finality about it.

In summary, if whatever you are equating can be conceived as a process that changes and develops over time, then you want to be using になる instead of です.