某些固定词组中不用冠词
(1)与by连用的交通工具名称前：by bus乘公共汽车;by car乘汽车;by bike骑/坐自行车;by train乘火车;by air/plane乘飞机;by sea/ship乘船，但take a bus，in a boat，on the bike前需用冠词。
(2)名词词组：day and night日日夜夜;brother and sister兄弟姐妹;hour after hour时时刻刻;here and there到处。
(3)介词词组：at home在家;in surprise惊奇地;at noon在中午;on foot步行;at night在晚上;on duty值日;at work在工作;on time准时;for example例如;in class在上课;on show展览;in bed在床上。
(4)go短语：go home回家;go to bed上床睡觉;go to school去上学;go to work去上班;go shopping/swimming/boating/fishing去买东西/游泳/划船/钓鱼。