It has been a while since I have seen a lamp. hey guys, I watched Ellen show today. and I heard Ellen said "It has been a while since I have seen a lamp" normally,i see this structure of sentence,like : It has been a while since + past tense. for example, It has been a while since I saw a lamp or It has been a while since I first saw a lamp. what are the differences between "It has been a while since I have seen a lamp"and" It has been a while since I saw a lamp"?