Could someone trademark a fairly common string of words, like "This is Your Life" or "Ask [Name]"? My question specifically regards to the naming a podcast — not naming a business. There is a podcast named that, which is fairly popular on iTunes, but if someone else started a podcast with the same name, could the original creator sue?
Just to be clear, I do not want to name a podcast with the same name(s) mentioned above or anything along those lines — it's just a general question.