holiday
1.holiday不一定指“一天”，如We have a holiday every Saturday里的holiday指一天，但We take a month's holiday every year里的holiday并不指一天，却指“假期”。所以We have five holidays this term是“在本学期里我们有五次放假。”未必指五天放假。但复数形式holidays往往被用来指一天以上的假期，所以summer holiday跟summer holidays意思相同，a holiday of two months, a two-month holiday和two months of holiday(s)也意思相同，其中，第三种表达最不普通。
“连续五天放假”不可说five holidays，该说a holiday of five days, a five-day holiday或five days of holiday(s)，第三种表达最不普通。
2.holidays有时用作单数，如One Christmas holidays she visited us。
3.holiday有时用作抽象名词，如the joy of holiday和six months' holiday。
4.可以说a few days' holiday, three whole days' holiday等，那days后的撇号省去也可以。
5.星期日往往不算作holiday，如可以说on Sundays and holidays。
6.on holidays里的holidays指元旦、国庆节等放假日，in the holidays里的holidays指“假期”。
7.make holiday里没有a, take a holiday里有a（两种表达方式都作“休假”解）。on holiday和on a holiday都可以说。各种表达方式都含有“玩”的意思，不论指一天或多天都可以。例如：
- They are making holiday（或taking a holiday）in the country today.
- When they were making holiday（或taking a holiday）in the country last month, they read together every evening.
- They are on (a) holiday today.
- They have been on (a) holiday for days.
