『a holiday』：每個人都放假的日子，例如宗教、節慶或國定紀念日，通常這些假日是法定假日，當美國人提及 the holidays/the holiday season，他們指的是包括Christmas, Hanukkah(猶太人聖節), 以及New Year's Day的這段假期，如 New Year holiday, a legal holiday, a national holiday。但不包括週末，如果是週末必須說on a weekend。
on holiday/on one’s holiday 休假中
I am going to take a week’s holiday in June.
May 1st is a holiday in many European countries.
如 summer vacation, winter vacation, annual vacation, Christmas vacation。
go on vacation/ take a vacation 自己放假
be on vacation 度假中
They are on vacation now. (on 後面不接任何冠詞)
I am planning on visiting my parents during Christmas vacation.
He plans to go on vacation for most of July.
『days off』:純粹指不用上班，休息的日子或一段時間，例如週末，就是days off。
He has a day off today.
She had two weeks off because she was ill.
I want to take a day off to see the doctor. (我想自己一天不上班去看醫生。)
I got an afternoon off and went to the ball game. (請兩小時假看球賽。)
如ask for leave （請假）grant leave （准假）overstay one’s leave （超假）sick leave （病假）maternity leave（產假）annual leave（年假）。
go home on leave請假回家
take one’s leave告辭
take French leave不告而別
I met her while I was on leave.
She is on six week’s paid leave. (她正在度六週有薪假期)
I get leave twice a year. = I have two leaves a year. (我一年有兩次休假)
have/take a break 休息一下
Give me a break! (饒了我吧)
There was a break in the concert.
Let’s have a coffee/tea break.
They usually go shopping during their lunch break.