Interpretation

Hi, Dozy!

It was not until she entered the classroom that she realized she left/had left her book.

I have two questions:
  1. Which one in bold should I use?

  2. Which action takes place first:
    entering the room or realizing that …

On the whole, firstly, she entered the room and then realized...
or vice versa...

Please, help me understand the meaning of the sentence…

Many thanks...

You need to specify a place where she left it, like “she had left her book at home”. If you don’t want to specify a place then you should use “forgotten” rather than “left”.

In this case the past perfect (“she had left/forgotten”) is correct. You may sometimes hear people not bother (so you might hear “… she realised she forgot her book”), but this is not such good English.

She realised as she entered, or shortly after she entered.

A marvellous comment!!! It is not compliment, It is FACT!!! Thank you!..

Dozy,

  1. She realized she had forgotten her book.
  2. She realized she had forgotten her book at home.
  3. She realized she had forgotten her book to take at home.
  4. She realized she had forgotten her book to take from home.
    Which one is more correct?

#1 is correct. The others are incorrect.

Dozy,
You branded all are wrong except #1.
2. She realized she had forgotten her book at home.
For # 2, I mean “She realized she had forgotten to carry her book which was at home.”
How to express this idea in a short form?
3. She realized she had forgotten her book to take at home.
For #3, She realized she had forgotten to take her book which was left at home.
How to express this idea in a short form?

  1. She realised she had left her book at home.
  2. As (2).

Dozy, it was not until she entered. i do not understand meaning

She realised she had forgotten her book as she entered the classroom, or shortly afterwards. She did not realise this before she entered the classroom.

Hi Dozy, thank you. are as or before same meaning?

as - at the moment that
before - prior to

Thank you very much coach

Dear coach, I want to know meaning-i am bold enough to dare his anger.

This use of “dare” is not natural English. It may mean something like “His anger does not scare me” or “I am not afraid of provoking him”.

Thank you

Dear, ‘i did not realize in an attempt to enjoy that’ my question is why preposition ‘in’ used

The fragment you have posted is not a complete sentence, and does not appear to make sense, so it is impossible to provide an explanation as to why ‘in’ would have been used there, sorry.

Hi Dozy,

You can also use here:

No sooner had she entered the class room then she realized to leave her book at home.

Do you think that is relevant here?

No sooner … than
No sooner … when but no sooner … then isn’t possible. It’s in the same category as your

Yes, Alan; here needs Conjunction “than” rather Adverb “then”.