I'd be grateful to know the difference between the two sentences in terms of giving permission. That is why 'might' can be used in the first sentence while is wrong in the second:
You ___________ leave if you've finished.
You ________ use my dictionary if you want.
Thanks in advance.
'Might' is unnatural in both, 'May' is possible.
Context is always important; labelling is rarely important.
That was absolutely clear before I saw this (Q1) Could it possibly be a typo?![]()