to be on summer vacation ☊ 
kỳ nghỉ hè kỳ nghỉ lễ ngày nghỉ ngày lễ 
vacation like: nghĩ hè → →
die Sommerferien ☊ 
nghỉ hè ☊ 
☊ Okay, ich rufe das Hotel an, in dem ich in den Sommerferien war. ☊ OK, anh sẽ gọi cho khách sạn mà anh đã ở vào kỳ nghỉ hè. ☊ (Lektion 42, Nr. 610) I'm afraid Mr Walsh is away on holiday this week. ☊ holiday ☊
We went on holiday together last summer. ☊ holiday ☊
a summer/holiday/Saturday/vacation job ☊ job ☊
The hotels are always full during the peak season (= when most people are on holiday/vacation). ☊ season ☊
We are very busy—so much so that we won't be able to take time off this year. ☊ so ☊
the summer holidays/vacation ☊ summer ☊
the long vacation (= the summer vacation) ☊ vacation ☊