teng

/ teŋ /

Cases

SingularPluralWhen to use it
nominative teng the friend tengle the friends the plain dictionary form — the doer of the sentence
genitive tengni the friend's tengleni the friends' the owner — whose it is
accusative tengni the friend (as the object) tengleni the friends (as the object) a specific, known object — whom or what
dative tengge to the friend tenglege to the friends direction or recipient — to where, to whom
locative tengde at / in the friend tenglede at / in the friends where it is; also having — mende bar, "I have it"
ablative tengden from the friend tengleden from the friends 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 tengim my friend tenglerim my friends
your tenging your friend tenglering your friends
his / her tengi his / her friend tengleri his / her friends
our tengibiz our friend tengleribiz our friends
you all's tengigiz you all's friend tenglerigiz you all's friends
their tengleri their friend tengleri their friends

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