When to use 'baa', or 'buu', 'bey', etc.

When the focus is on the subject, then use 'baa'

Shimbirta yaa diley? - Who killed the bird?
Aniga baa diley       -  I killed it

When focus is on the object then you use 'buu', 'bey', 'baan' etc.

Wiilku, ma shimbir buu dilay?  Haa.
                   (OBJECT)

Did the boy kill a bird? Yes.


Ninkii naagtii     buu           arkey  
SUBJECT OBJECT FOCUS-WORD      VERB

It was the woman whom the man saw
(he didn't see a child, or a horse etc.)

Ninkii      baa            naagtii    arkey
SUBJECT FOCUS-WORD        OBJECT     VERB

It was the man who saw the woman
(It wasn't a child who saw the woman)

Ninkii    naagtii    baa            aragtey
OBJECT      SUBJECT   FOCUS-WORD       VERB      

As for the man, it was the woman who saw him
(He wasn't seen by a old man, etc)


Note: I said before that the subject always comes at the beginning. I was wrong, it doesn't have to. But, usually the TOPIC of the sentence comes at the beginning. In these sentences, the topic is 'Ninkii'. But in the last sentence, the subject is not 'Ninkii' it's 'naagtii' .