One peculiarity of Tok Pisin is its number/plurality distinctions. 
Tok Pisin has not only the usual singular, dual and plural, but also trial.
There are no gender distinctions and the words do not need to be modified when 
their either the object or subject. Here is a simple explanation of the pronouns:
   yu (you)
   yutupela (you, 2)
   yutripela (you, 3)
   yupela (you, 4+)   

This unusual plurality distinction is very useful and even more 
adept than English in articulating different forms of us.
     Mi (me)
     mitupela (me and someone else -not including you)
     yumitupela (us -you and me)
     mitripela (us -me and two other people, not including you)
     yumitripela (us -me and you two)
     mipela (us -me and an indefinite amount of other people not including you)
     yumi (us -me and you indefinite #)
     In speech these words are often shorten and simplified for example:
 mitupela (me and someone else) could be mitupla or mitla. 
It is not uncommon for words to be shortened and simplified in Tok Pisin,
 and since there are no official rules, words trend towards becoming increasingly blended and shortened. 

Third person pronouns: it, him, her, he, she. 
     Em (singular, derived from him.)
     emtupela (those/these, two)
     emtripela (those/these, three)
     ol (they, those/these indefinite#)
     With these, whether it is those, these or whatever can be made more specific by utilizing long or bilong.

Index - Sounds