妈妈对儿子说：
"Jimmy, we don't have any suger. Will you pop over the road to the shop and buy a packer?"
pop over: 赶到
又如：My new neighbours across the road had just moved in so I popped over to see them.
Derek对他的朋友Bob说：
"Bob, old Mr.Smith on the second floor is very lonely. I said I'd pop round tonight and keep him company."
pop round:去做客（时间不确定）
又如：A: Would you like to pop round one night this week? Would Wednesday evening suit you? B: I'd love to.
Brenda和老公Sam的对话：
"Sam, where did you buy that beautiful tie?"
Sam:" I needed a new tie, so I popped into the department store and bought it."
popped into:To move quickly or unexpectedly 突然冲入
又如：The farm popped into view as we turned the corner.
小结：
1. pop in, pop out, pop up和pop over基本都是appearing or disappearing (popping out) briefly and casually的意思。
2. 当然，pop out 还有另外一个含义：burst open with a short sharpish sound 突然爆开，发出砰响
例如：He had shaken the champagne bottle and the cork popped out before he was ready to pour.