休日に学校があるなんて思わなかった。って英語でなんて言うの？

A public holiday is a day where most businesses and institutions are not open. Thus, it is unusual that you would need to attend school on that day. To say that something is unusual or unexpected you can make an exclamation like "How strange!" or "How bizarre!".

Keywords; I didn't know... I didn't expect... Saying you didn't know of or expect something implies that you had no clue or idea. It also means that you may be surprised by something or caught off guard. You may also say the following; I was surprised to hear that we still have to attend school in the holidays.

"What's going on!" is a common expression of surprise when someone is faced with an unusual or unexpectedly challenging situation.

This sentence focuses on the fact that it was strange and unexpected in your opinion that you had classes on the holiday. This sentence is based upon American English but any native English speaker should understand what you want to say. I hope this helps :)

"flabbergasted" means surprised or taken off guard, and is an expression that some native speakers, especially younger generations like to use. For example: I was completely flabbergasted when he asked me on a date. "I was flabbergasted that we had school on a holiday!"

If you think or expect something to happen then you day you 'assumed' or 'thought' a public holiday is a day when alot of shops/business do not open as the employees have a day off as well so you might think that the school would not be on as well

"Even though it was a holiday, for some reason our school was open." The phrase "even though" clarifies that a particular circumstance has no effect on the outcome of the situation. In this sentence "Even though it was a holiday, for some reason our school was open." The circumstance of the situation is that it's a holiday, but "holiday" has no effect on the outcome of the situation which is the school being open. "Although it was a holiday, I still had to attend school." The word "although" clarifies that a particular circumstance has no effect on the outcome of a situation. The circumstance of the situation is that it's a holiday, but "holiday" has no effect on the outcome of the situation which is attending school.

This is a way of asking a question to figure out why something is happening. So in this scenario the children still have to go to school even though it is a holiday and they would like to know why this is.

"I didn't think we had to go into school today" An expression used to describe that you thought/think you did not have to go to school on that particular day. "I thought it was school holiday?" 'Thought' is an expression used if you had once 'thought'/think/wondered something, ex. "I thought we had milk in the fridge" 'School holiday' is the term used when you don't have to go to school because it is the holidays.