You deal and open 1. Partner responds 1NT. You might play that as forcing, semi-forcing, or "nothing special". You need to make sure you and partner are on the same page. For our answer, we'll assume semi-forcing which means partner has up to 12 points and we are allowed to pass.
What is your action after 1NT with:
K109765
AQ32
A2
2
2. Always get the other major into the picture when you can. If you had 6-4 with a minimum, a decent major and a so-so minor, it would be okay to repeat your major. For example, with:
KQJ987
A2
J876
2
a 2 rebid would be acceptable.