If you are asked: あしたなにをしますか。(What are you going to do tomorrow?)
and if you “don’t know yet,” the recommended answer is: わかりません, not しりません.
Last Monday, I talked about しりません for “I don’t know” and I’m saying now that しりません doesn’t suit here. Why?
しりません actually means “to have no knowledge of something” but about tomorrow, you are likely to have some idea about what might be happening or what you may be doing. You just don’t know it for sure yet. If you say しりません in this situation, it sounds like you are refusing to talk about it any further and the asker will get quite often offended.
On the other hand, わかりません can imply “I don’t know it well enough to explain it” so the asker can still keep talking to you. That is the reason why わかりません is better in this situation.
わかる | EasyJapaneseE
8 July 2020 at 8:02 am[…] for the translation of “わかる.” As I wrote in my previous articles, わかりません and わかりません(2) , わかる overlaps with the English verb “to know” but you […]