Many people player The Elder Scrolls V: Skyrim are having trouble completing the quest "Assist the People of Falkreath" to become Thane of Falkreath. The issue is caused by players thinking they have helped at least three people in the town, however they do not register in the quest itself. The video below shows all the information needed to pass the quest, becoming Thane of Falkreath.
To summarize what you need to do:
Go to the inn in Falkreath
Talk to the elderly looking Nord in the inn to start a quest to take his friend's ashes to the graveyard located in Falkreath
After talking to the Elf you give the ashes to, start his quest to return his journal to him
During the time your taking the ashes to the cementary, you should come upon a scene depicting a man and woman grieving the loss of their daughter and get another quest from them
LAST BUT NOT LEAST, take at least one cabbage to the farmer located in the center of Falkreath to finish the quest "Assist the People of Falkreath"