I just understood something about Korean by analyzing English

sentences written by Korean speakers.

Korean speakers tend to write a lot of passive voice sentences in English:

A gift was brought by him.
The taste of the food was changed by her.

etc...

These sentences are grammatically correct but sound very strange to an English speaker. English speakers usually avoid the passive voice. They prefer the active voice:

He brought a gift
She changed the taste of the food (by adding more salt, etc)...

To us, the subject or topic is the person or object that acts the verb out. That is usually what we start our sentence with.

The concept of subject or topic in Korean is difficult for most Western language speakers to grasp. But I think I understand better now:

In Korean, the subject or topic is not necessarily "active" in the sentence. It is maybe just the thing or person that, if ommitted from the sentence, would make the sentence incomplete and grammatically incorrect:

He brought a...
She changed the...

I know this explanation is not complete and there are surely other things to take into account but maybe... I am getting closer to understanding... Fingers crossed. And back to work😂~