I came across this blog today- http://www.uskal.net/2009/01/mari-belajar-bahasa-dusun.html#comments. (Forgive me for having not known before). I must say I am so pleased to see that people are actually discussing the language :-). I share the wish of many, that one day there will be a simplified grammar of Dusun for people to refer to.
Anyway, somebody asked what is the difference between 'luyud' (flood) and 'lumuyud' (flood). There is no simple way of answering this, except that to say 'luyud' is the root word (kata akar) and 'lumuyud' is the affixed word (kata imbuhan). For speakers of Malay, we can almost say that:
luyud = banjir
lumuyud = kejadian banjir (membanjir , although membanjir sounds a bit weird).
Most of the time, 'lumuyud' is used to refer to the action as in:
(1) Lumuyud i bawang do Liwogu (The Liwogu river is flooding)
but it can also be used to refer to the river that is flooding as in:
(2) i lumuyud (the one that is flooding = the river that is flooding)
How, then, can we tell the difference of uses?
When a word that has -um- in it is used to refer to the action, it is normally used in the beginning of a sentence like (1) When it is used to refer to an non-action, it is always preceded by 'i' or 'o' that function somewhat like the English article 'the', like in (2). Of course it can also be preceded by words like 'iti' (this), and 'ino' (that), which basically tells that it is functioning like a noun (kata nama).
There you go...I was in my language-teacher mood, hence, this topic :-)