yes i get mine to say sorry - i always explain what they have done/said to upset someone try and make them understand and ask them to appologise
my older 2 can understand the importance of saying sorry and showing that they are because they understand how it feels when they have been made to feel sad and i just remind them of this
DS2 is 2.5yr and he can say sorry etc but doesn't really understand why half of the time although i explain in simple words to him so he will either say sorry or offer a kiss/hug to whoever it was
DS3 is only 13 months so a little young yet although he pinches/bites occasionally and i still encourage him to hug and to be gentle