sneak up
phrasal verbsneak up (on somebody/something)
- to move towards somebody very quietly so that they do not see or hear you until you reach them
偷偷走近 - He sneaked up on his sister and shouted ‘Boo!’
他偷偷溜到妹妹身边，然后大喊一声 “嘿！”
- He sneaked up on his sister and shouted ‘Boo!’