Make conditional sentences: 1) he will not go to see the play as he was present at the dress rehearsal. 2) he went to moscow specially to hear this famous singer because he is fond of him. 3) we did not go to the refreshment room to have a glass of lemonade because we were not thirsty. 4) she couldn't mend her dress herself because she had no needle.

1) If he hadn't been present at the dress rehearsal he would go to see the play.
2) He wouldn't have gone to Moscow specially to hear this famous singer if he wasn't fond of him. 
3) We had gone to the refreshment room to have a glass of lemonade if we had been thirsty.
4) She could have mended her dress herself if she had had a needle.