Small Big for Young Old
I’m two years smaller than you. She’s three years bigger than me.
I’m two years younger than you. She’s three years older than me.
Great refers to the importance of a person or thing; Napoleon was a great man, Homer’s Iliad is a great book Use great with words like distance, height length, depth. There is a great distance between the earth and the moon, informally, use great to mean something nice or good. We watched a great concert last night. If reference is to age, say young or old. Small and big usually refer to size He is big (or small) for his age.