Opening at the three level

An opening bid at the Three-level shows a good seven-card suit, but less than opening values. The more you have in your suit – preferably two of the top three cards or three of the top five – and the less outside, the better.

Hand A: Open 3♠.
Hand B: Open 3♦.
Hand C: Pass-heart suit quality too poor.

Responding to Three-level opener

"Put up or Shut up" - probably "Shut up". 

With Hand (a), bid 4♠. You have a magical queen in partner’s suit and three quick tricks outside.

With Hand (b), you should pass. Those queens and jacks are probably completely useless – partner will be out of the suit once they start to work. Aces (and to a lesser extent) kings are what partner wants. I’d be surprised to see partner make even 3♠.

Pass with Hand (c) too. Partner has told you they have a useless hand unless spades are trumps. 4♥ would be very likely to fail.