By Rabbi Chaim Chazzan
I’m aware that there is a prohibition of hachono – preparing on Shabbos for after Shabbos. May one study on Shabbos for a test?
There are several forms of preparation which are prohibited on Shabbos:
“Mimtzo cheftzecha” – one may not do something permissible on Shabbos in preparation for a weekday activity which is prohibited on Shabbos.
“Vedabair davar” – forbids even verbally expressing one’s plans to do those activities.
“Hachana” – forbids preparation for after Shabbos even when the activity itself and what it is facilitating are not related to anything prohibited on Shabbos. An example would be to bring a bottle of wine from the cellar for havdalah. There are several conditions that are required to be present in order for an activity to be classified as hachana, a discussion of which would be beyond the scope of this article.
A preparation that addresses a present Shabbos need, even if the act also serves as a post Shabbos preparation, is permitted. As example would be clearing off a table from shalesh seudos if the table is needed or the messy appearance of the room is disturbing.
It follows that it is permitted to study for a test on limudie kodesh because the mitzvah to study Torah applies on Shabbos, therefore when studying Torah one is fulfilling a “need” for Shabbos, despite it also serves as a post Shabbos preparation. However, verbally expressing one’s post Shabbos motive is possibly forbidden on Shabbos.
Some forbid studying for a test on secular studies, but others doubt whether this is prohibited.
 שוע”ר סי’ שז ס”א, וסי’ תק”ג ס”ג.
 משנ”ב תרס”ז ס”ק ה. סי’ זה בשוע”ר לא הגיע לידינו
 שוע”ר סי’ שב ס”י
 שש”כ פכ”ח ספ”ד ובהערות
 בשש”כ שם הע’ קסט מסתפק ע”פ משנ”ב סי’ רצ ס”ק ד וכ”כ בשוע”ר סי’ רצ ס”ו
 שם הע’ רו הסתפק הגרש”ז אוירבאך, אכן ראיתי במלקטים שיש מחמירים