tankist

/tankist/

Cases

SingularPluralWhen to use it
nominativetankistthe tank crewmantankistlethe tank crewmenthe plain dictionary form — the doer of the sentence
genitivetankistnithe tank crewman'stankistlenithe tank crewmen'sthe owner — whose it is
accusativetankistnithe tank crewman (as the object)tankistlenithe tank crewmen (as the object)a specific, known object — whom or what
dativetankistgeto the tank crewmantankistlegeto the tank crewmendirection or recipient — to where, to whom
locativetankistdeat / in the tank crewmantankistledeat / in the tank crewmenwhere it is; also having — mende bar, "I have it"
ablativetankistdenfrom the tank crewmantankistledenfrom the tank crewmenwhere it comes from; also "than" when comparing
When to use each case
nominative
the plain dictionary form — the doer of the sentence
genitive
the owner — whose it is
accusative
a specific, known object — whom or what
dative
direction or recipient — to where, to whom
locative
where it is; also having — mende bar, "I have it"
ablative
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
mytankistimmy tank crewmantankistlerimmy tank crewmen
yourtankistingyour tank crewmantankistleringyour tank crewmen
his / hertankistihis / her tank crewmantankistlerihis / her tank crewmen
ourtankistibizour tank crewmantankistleribizour tank crewmen
you all'stankistigizyou all's tank crewmantankistlerigizyou all's tank crewmen
theirtankistleritheir tank crewmantankistleritheir tank crewmen

The overlap in the last rows is real, not a mistake: tankistleri can mean "his / her tank crewmen", "their tank crewman", or "their tank crewmen" — context decides.