This is the 83rd most frequent Estonian word.
mängu
The Estonian word "mängu" is the genitive or partitive form of "mäng," meaning "game" or "play."
In this sentence, 'mäng' is again in the genitive case ('mängu'), modifying the word 'kaaslaseks' to describe the purpose or activity requiring the teammate.
Ta viis mind mängu kaaslaseks.
He brought me along as a teammate for the game.
In this sentence, 'mäng' is in the partitive case ('mängu'), referring to an activity or a game being played.
Lapsed mängivad rõõmsalt mängu.
The children are joyfully playing a game.
Here, 'mäng' is in the genitive case ('mängu'), indicating possession or defining another noun, representing 'the game's beginning'.