DI

di(1)

di(2)

的确 = di(2)que(4) = really, indeed

的确对不起 = di(2)que(4) dui(4)bu(-)qi(3) = really sorry

di(3)

底 = bottom, base; used to designate bottom-located radicals in Chinese writing.

走字底 = zou(3)zi(4) di(3) = the bottom  'leave' character of the Chinese  wriring system: 辶

di(4)

地 = earth, land

地板 = di(4)ban(3) = floor (of a room or building)

板 = ban(3) = board (flat piece of hard material)

*****

弟 = younger brother

The usual form is duplicated, even if there is only one younger brother.

弟弟 = di(4)di = younger brother, younger brothers

哥哥 = ge()ge() = older brother(s)

Please note: even if the reference is only to one older brother, it's not just 哥, but 哥哥.

An alternative word for elder brother is:

兄 = xiong(1) = elder brother

兄弟 = xiong(1)di(4) = brothers (if there is at least one older and one younger)

兄 is never used alone. If there is no younger brother to be referred to, the following term is used:

兄长 = xiong(1)zhang(3) = brother, brothers (if he or all are older)