başçı

/ baʃtʃɯ /

Cases

SingularPluralWhen to use it
nominative başçı the leader başçıla the leaders the plain dictionary form — the doer of the sentence
genitive başçını the leader's başçılanı the leaders' the owner — whose it is
accusative başçını the leader (as the object) başçılanı the leaders (as the object) a specific, known object — whom or what
dative başçığa to the leader başçılağa to the leaders direction or recipient — to where, to whom
locative başçıda at / in the leader başçılada at / in the leaders where it is; also having — mende bar, "I have it"
ablative başçıdan from the leader başçıladan from the leaders where it comes from; also "than" when comparing

The endings are the same ones the pronouns wear — that page explains when each case is used.

With an owner

One ownedSeveral owned
my başçım my leader başçılarım my leaders
your başçıŋ your leader başçılarıŋ your leaders
his / her başçısı his / her leader başçıları his / her leaders
our başçıbız our leader başçılarıbız our leaders
you all's başçığız you all's leader başçılarığız you all's leaders
their başçıları their leader başçıları their leaders

The overlap in the last rows is real, not a mistake: başçıları can mean "his / her leaders", "their leader", or "their leaders" — context decides.