He used riddling to talk to Smaug I think because he wanted to stall and waste time as he figured out a plan. He also used riddles to talk to Golem who he clearly was trying to stall to save himself as Golem wanted to kill and eat Bilbo. So it is a reoccurring theme of Bilbo and it makes sense.
Answer: an invasion of a castle.
Explanation: "They enter my castle wall!"
I hope this helps :)
Answer:
A search engine provides accurate search results OR answers for the persons" questions.
Explanation:
Answer:is that the whole problem?