What is the more natural way of saying: "I will be busy this Friday."


I only know hiragana and katakana at this stage, so pardon the long sentence;
I'm learning from the "Japanese From Zero!" books. In the book, the answer it
gives for "I will be busy this Friday" is:

> こんしゅうの きんようびは いそがしいです。

This is in response to someone asking to hang out on Friday. I used に instead
of は when translating it. It seems to me that the literal English equivalents
would be "This Friday is busy." vs. "On Friday, I will be busy." Are the
sentences equal either way in Japanese, or is one more natural than the other?




>   1. こんしゅうの きんようびは いそがしいです。
>   2. こんしゅうの きんようびに いそがしいです。
>

Both are grammatical and translate to "I will be busy this Friday" in English,
but they are used in different situations. Sentence 1 is used as a reply for
"Hey, can we have a meeting this Friday?", whereas Sentence 2 is used as a
reply for "Which day of this week are you busy?"

In Sentence 1, きんようび is marked with the topic-marker は. Japanese is a [topic-
prominent language](https://eastasiastudent.net/study/topic-prominent/) and は
is used to mark what you are talking _about_. Your literal translation will
not help you understand the difference because English is a subject-prominent
language. In essence, Sentence 1 is saying "Regarding this Friday, (I am)
busy." If someone has already mentioned "this Friday" in the conversation and
you need to say something about it, it's natural to mark it as the topic of
the sentence.

