1. The Gemara has a lengthy discussion regarding when partners are obligated in certain Mitzvos.
2. Partners are obligated to bring Bikurim.
3. Partners are obligated to put a gate on a roof.
4. If a person borrows a four-cornered garment, he is exempt from putting Tzitzis on it for thirty days.
5. One cannot proclaim that all of his grain is Terumah.
A BIT MORE
1. For example, the Torah states, "Your (plural) Ma’asros" in order to teach that partners must give Terumos and Ma’asros. However, as we mentioned earlier, Rebbi Ilai indeed holds that partners are exempt from Reishis ha’Gez.
2. They are also obligated to put Tzitzis on a four-cornered garment.
3. This is derived from the verse explaining the reason for the law, "For the person who falls will fall from it." This implies that as long as a person can fall off this roof the owner or owners are obligated to put up a fence.
4. This is derived from the verse, "your clothes," implying that according to Torah law one must own the garment in order to be obligated to put Tzitzis on it.
5. Similarly, one cannot make a dough and proclaim that the entire dough is Challah.