mcmc

for puts you are thinking of it backwards- you are thinking of calls. a put allows the investor, not the issuer, the ability to put the bond back to the issuer and get paid at par usually.
so let's say your bond was at par, 100. interest rates rise. now your bond is worth 95 if it were non-callable. a puttable bond you are able to cash about and put to the issuer and get paid your 100. make sense?

sinking fund- bond is worth 100. every year in the sinking fund the co. retires part of the bond, usually at par. keep this example going.... maybe after year 1 it's only 10% retired, but you retire it at 100 when the bond is worth 95 and the kicker- interest rates have risen so guess how your reinvestment of that cash is looking? pretty good.