1.   The  primary  obligation  of  the  bailor  is  to  allow  the  bailee the use  of the thing loaned for the duration of the  period stipulated  or  until  the  accomplishment  of  the  purpose  for which the commodatum was constituted

a.    However,  the  lender  may  demand  its  return  or temporary  use  if  he  has  the  urgent  need  of  the thing   or   if   the   borrower   commits   an   act   of ingratitude

2.   PRECARIUM:  a kind of commodatum where the bailor may demand the thing at will.  In this kind of commodatum, the lender  may  demand  at  will  the  return  of  thing  under  the following circumstances:
a.    If neither the duration of the contract nor the use to  which  the  thing  loaned  should  be  devoted,  has been stipulated; or
b.   If  the  use  of  the  thing  is  merely  tolerated  by  the owner.
c.   the law recognizes the urgency as well as it is gratuitous.
d.   Take note that in precarium, there is no stipulated period or the use is merely tolerated

3.   He  may  demand  the  immediate  return  of  the  thing  if  the bailee commits any act of ingratitude
a.    If the bailee should commit some offenses against the person, honor or the property of the bailor, or
of   his   wife,   and   children   under   his   parental authority
b.   If  the  bailee  imputes  to  the  bailor  any  criminal offense or any act involving moral turpitude, even
though he should prove it, unless the crime or act has  been  committed  against  himself,  his  wife  and
children under his authority
c.    If  the  bailee  unduly  refuses  the  bailor  support when the bailee is legally or morally bound to give

4.   He has the obligation to refund extraordinary expenses for the preservation of the thing loaned—it is him who profits from the said expenses anyway.  
a.    As  a rule,  notice is required because it is possible that   the   bailor   may   not   want   to   incur   the
extraordinary expenses at all
b.   An  exception  of  course  is  where  there  is  urgency that the reply to the notification cannot be awaited without danger
c.   you  have  to  determine  if  its  ordinary  or extraordinary
d.   why    would    you    advance    for    the extraordinary  expenses  when  you  can  return  the
thing and make the lender pay for the expenses?
5.   Regarding, extraordinary expenses arising from the actual use of the thing, the division of liability between the bailor and bailee is 50-50.  This is the default rule but the parties may stipulate for a different apportionment. 

6.   For expenses  other than  ordinary expenses and  expenses for the preservation and use of the thing, the bailor is not liable for the same. 

7.   He  is  liable  to  the  bailee  for  damages  in  case  he  has knowledge  of  flaws  of  the  thing  loaned,  and  he  didn't advise the bailee of the same
a.    There is flaw or defect in the thing loaned
b.   The flaw or defect is hidden
c.    The bailor is aware thereof
d.   He doesn't advise the bailee of the same
e.    The  bailee  suffers  damages  by  reason  of  the  said flaw or defect
8.   He cannot excuse himself from liability for any expense or damages by abandoning the thing to the bailee