All I knew about<i> though</i> in conversation was <i>but</i> until I heard this sentence today.<br/><br/>A: ~~<br/><br/>B:~~<br/><br/>A: I think a cell phone will be a good birthday gift for his birthday.<br/><br/>B:<u>But</u> I don't think he needs a new cell phone <u>though</u>.<br/><br/>But and though are in one sentence. What is it?(How it is different from the sentence without <i>but</i>?)