Learning to speak through play and activities of daily living is how children typically learn language. All children benefit from a rich language environment. There are many ways to build vocabulary in a naturalistic environment.
For children, the naturalistic environment is home.
For example during play with a ball a child may say "ball". The caregiver can expand the communication by saying "oh you want your ball". The caregiver
can then add words during the game at appropriate times. Words such as "more","my turn", "your turn"."up", "down" "roll the ball" and "bounce the ball" can be added, to name a few.