だいじょうぶ and いいですか

What is the difference between だいじょうぶ    and   いいですか  and how they are used?  Thanks.

こんにちは (Konnichiwa) ClaudiaR-sc5G,

Thank you for your question.

When being used to ask a question, 大丈夫ですか (daijōbu desu ka) and いいですか (ī desu ka) are virtually interchangeable. They both mean “is it okay?"

First of all, they can both be used to confirm understanding. Imagine a teacher giving instructions to a class full of students. At the end of their explanation, they might say 大丈夫ですか daijōbu desu ka) or いいですか (ī desu ka) to check that everyone is on the same page.

They can also be used to ask about someone's availability. For example, you might use these to ask your boss if now is a good time to talk. In this context, 大丈夫ですか (daijōbu desu ka) is slightly more polite.

Lastly, you can use either of these with the 〜て (~te) form to ask for permission. For example, if you need to leave work early you would say to your boss:

早く帰ってもいいですか？ (Hayaku kaette mo ī desu ka?) “May (I) go home early?"

早く帰っても大丈夫ですか？ (Hayaku kaette mo daijōbu desu ka?) “Is it okay if (I) go home early?"

In this context, 大丈夫ですか (daijōbu desu ka) is slightly more polite. 

The only real difference that comes to mind is that you can ONLY use 大丈夫ですか (daijōbu desu ka) when you want to how someone is feeling. For example, if your friend is looking a little pale, you would ask them how they are feeling using 大丈夫ですか (daijōbu desu ka) “are (you) okay," not いいですか (ī desu ka).

I hope this helped. Please let me know if you have any other questions.

勉強を頑張ってください！ (Benkyō o ganbatte kudasai!)
 

Thanks, Emma!  That makes it very clear.  I knew I'd get a perfect answer here.  Thanks again.