In Second seat bid 1 Spade.

In 4th seat if Responded bids pass.  If responder has passed bid 1 Spade

Pass!  A long bad suit.

Over 1Club bid 1D.  There are enough points to bid at the 2 level (10+ HCP).

A good bid in 4th position to give partner a lead.

In second position you can bid at the two level.  Over a Diamond opened this forces the responded to the 2 level.

Pass in the 4th position.

There is not a good bit for 2nd seat.  Double would say you could accept Clubs.  

A bid that is useful if the Responder Bids a Club or supports the Diamonds would be "Double".  This is a "Negative Double" telling your partner you have Hearts and Spades.  

After an opening bid of 1 Club, the 1 Spade overcall pushes the responder to the 2 level (10+ HCP)

In 4th position pass if Responded bids.  You don't have the Ace so telling partner to lead Spades is not of benefit.

Bid 1 Spade in second seat.  Also bid 1 Spades in 4th seat even in compettion.

North 1H

East - 1 S

South - Pass

West - Pass

North - 2 H

All Pass

North - 1H

East - Pass

South - 3 H

West - 1 S Looks like a Heart contract so partner please lead a Spade/

North - 4 H.  

1- D With equal numbers in a suit bid the higher one first.

1 - H

East 2 - D  Some support

2 - H Some support

N - 3 D

All Pass.  

The bid by east kept N/S from finding game in 3NT.

North -  1C

East - 1 H  I always bid my Major first.

South - Pass

West - Pass

North 2C

All Pass

The bid by east prevented South from bidding 1 H.  North still would have rebid the Clubs.