わからないままにしておきたくないって英語でなんて言うの？

Both of these sentences will work well. They both will let the teacher know that you did not understand or hear something clearly and that you really want to understand it before moving on. I hope this helps :)

I didn't quite understand = I don't understand it In the UK, we often moderate or soften our phrases by using such words as, quite, a little, fairly, rather. This often seems more polite and makes a phrase less dramatic. I'm not getting it = I don't understand it missing the meaning = not understanding something

This is a polite to ask the teacher to repeat.

I am not with you yet can you explain it in a different way I haven't quite grasped the content, can you go over it again I am not clear about ...... You can use all of these expressions to help gain clarification. 1. directly tells the tutor what you are unsure about and leaves it open as to how the tutor should explain. 2 indicates that you are uncertain about the meaning and need clarification. 3 tells the teacher you are unsure about the information and asks the teacher to repeat the phrase/sentence and to explain it again in a different way. To communicate effectively first think about your problem. If the tutor has already repeated the sentence/phrase but you dont understand it then the best option is to use phrase 3.

When you want to give a reason for why you want your teacher to repeat what they said; then you can say it in the following ways: -Could you please say that again because I'm not sure I understood what you meant -Can you please explain that in another way?

If you did not understand something properly then it is always a good idea to ask for someone to repeat it for me or to give another meaning or explanation as sometimes you don't always understand everything the first time. To explain something again is always a good idea or to explain in maybe a simpler way so it is easier to undertstand.