Does he go skateboarding once a week?
这个句子变一般疑问句,将助动词提前即可.只需注意助动词后跟动词原形
How often does she help you with your Chinese?
twice a week一周两次,所以疑问词选How often 多久一次
How is Katrina?
unhealthy表示健康状况,疑问词选择how如何,怎样
How many hours does Dina sleep every night?
eight hours 表示时间长度,提问数量疑问词选择how many
What helps you to study better?
good food and exercise表示物体,疑问词选择what什么.在此需注意,what作为一个代词,单复数不明确,通常当做单数对待,所以动词help要选择单三加S,用helps
此类题复杂多变,做的时候要谨慎小心,处处陷阱