从早上到现在一直在研究GST、HST，还是有几个问题不甚清楚，需要跟各位讨论，特别是jasong这样有经验而又古道热肠的朋友。
我去年做的事情比较杂，下面这些收入哪些要收HST/GST，哪些不要？
1. 心理健康培训，按小时收费。这项活动肯定是要收HST的，因为有一家客户在付款之前向我要了HST号码。
应税，注意2013年4月起恢复GST（5%），之前是HST（12%）。
2. 为一家出版社翻译了一本书。这家机构总部在美国，合约是通过他们的中国分公司签订，付款是通过paypal。 这应该不算在加拿大提供服务吧？为加拿大之外客户提供的服务要收HST吗？
（不需要，理解正确）
我这样理解的依据来自CRA网站：
A supply of a service made to a non-resident person is generally zero-rated. This includes supplies of Web site hosting and Web site design when provided by a
registrant to a non-resident.
Specific services are zero-rated if they are provided to a non-resident. These services include:
- an advertising service made to a non-resident person who is not registered for GST/HST purposes at the time the service is performed;
- instructing non-resident individuals in certain courses or administering certain examinations for those courses when the supply is made to a non-resident who is not an individual and is not registered for GST/HST purposes; and
- certain advisory, professional or consulting services made to a non-resident.
3. 我给中学生补习英文，似乎不要收HST。这样理解对吗？这应该属于 Exempt supplies，
（不需要，理解和引用再次正确，加分分）
many educational services such as:
- courses from a vocational school that leads to a certificate or a diploma to practice a trade or a vocation, or
- tutoring services for an individual who takes a course approved for credit by a school authority or the service follows a curriculum designated by a school authority;
