had better
［误］ You have better hurry.
［正］ You had better hurry.
［析］ had better只用过去时had，不要误用成现在时have。
［误］ You hadn't better worry.
［正］ You had better not worry.
［析］ had better后面加不带to的不定式，其否定式是"had better not+动词原形"。
half
［误］ I had driven about half mile.
［正］ I had driven about half a mile.
［析］ "半小时"有两种讲法half an hour, a half hour. 而"一个半小时"应讲an hour and a half或one and a half hours. "半天"应讲half a day，"半镑"应讲half a pound.但要尽量避免使用half a year，而应用six months；不用half a month, 而用two weeks或fifteen days.
［误］ Half us could go to the park.
［正］ Half of us could go to the park.
