We learn in the Mishna that performing half of the melacha of carrying is an issur derabanan but not min hatorah. Why is it not assur min hatorah, since we know that even a ‘chatzi shiur assur min hatorah’ (i.e. eating half a kezayis of prohibited food)?
The Gemara says that hammering out to broaden the chain around the animal’s neck is considered a ‘tikun’ (constructive change). Tosfos (D”H Bisherischan) states that animal chains are typically worn tightly. If so why do we consider it a ‘tikun’?
An un-pierced needle is not capable of becoming tamei, but can be moved on Shabbos. Rashi explains the reason it is not Muktzah is because it can be used for splinter-removal. Why is this reason not sufficient to render it a kli for tumah as well?