During or for?

Compare

They went to Florida during the winter.	They went at one point in the winter.
They went to Florida for the winter.	They went from the beginning to the end of the winter.

She phoned me during the week to tell me that she was getting married. (referring to a point in the week)

We were in the cinema for three and a half hours.

Not: … during three and a half hours.

Our flight to New York was delayed for seven hours.

How to use while

When is used to talk about two things that are happening at the same time. The length of time is not important. Remember that while is used with a subject and a verb (while + subject + verb). For example:

"The phone rang while I was watching TV."

• I've been meaning to call you ___ some time.
  
  during
  while
  for
  
• He fell asleep ___ the meeting.
  
  while
  for
  during
  
• We all stayed inside ___ the storm.
  
  while
  during
  for
  
• Someone stole my bag ___ I was riding on the train.
  
  while
  during
  for
  
• The dog was barking ___ she was trying to watch TV.
  
  for
  during
  while
  
• Please don't smoke ___ I'm eating.
  
  during
  while
  for
  
• Bats sleep ___ the day.
  
  during
  for
  while
  
• They've been out of the office ___ ages.
  
  during
  while
  for
  
• He kept talking to me ___ I was trying to read.
  
  during
  while
  for
  
• His mobile-phone rang twice ___ the film.
  
  while
  for
  during

https://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-87152.php

WATCH THE VIDEO AND INDICATE THE WRONG SENTENCE.

 The man's a lawyer.

 His client is convicted to a jail sentence although he didn't commit a crime.

 The client wants to take revenge on his lawyer.

 All the sentences are correct.

(To) Hit the books

Literally, hit the books means to physically hit, punch or slap your reading books. However, this is a common English idiom among students, especially American college students who have a lot of studying to do. It simply means “to study,” and is a way of telling your friends that you’re going to study. It could be for a final exam, a mid-term test or even an English exam.

“Sorry but I can’t watch the game with you tonight, I have to hit the books. I have a huge exam next week!”

2. (To) Hit the sack

Just like the first idiom, the literal meaning of this would be physically hitting or beating a sack (a large bag usually used for carrying things in bulk such as flour, rice or even soil). But actually to hit the sack means to go to bed, and you’d use this to tell your friends or family that you’re really tired, so you’re going to sleep. Instead of saying hit the sack you can also say hit the hay.

“It’s time for me to hit the sack, I’m so tired.”

https://www.learn4good.com/languages/toefl/toefl_stan_test1.htm