Question

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.

Answer 1

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.

Answer 2

I can help you make conditional sentences based on the information from the web search results . Here are some possible ways to rewrite your sentences using different types of conditionals:

1) He will not go to see the play as he was present at the dress rehearsal. - If he is present at the dress rehearsal, he will not go to see the play. (First conditional) - If he had not been present at the dress rehearsal, he would go to see the play. (Second conditional) - If he had not been present at the dress rehearsal, he would have gone to see the play. (Third conditional)

2) He went to Moscow specially to hear this famous singer because he is fond of him. - If he is fond of a famous singer, he will go to Moscow specially to hear him. (First conditional) - If he were fond of a famous singer, he would go to Moscow specially to hear him. (Second conditional) - If he had been fond of a famous singer, he would have gone to Moscow specially to hear him. (Third conditional)

3) We did not go to the refreshment room to have a glass of lemonade because we were not thirsty. - If we are thirsty, we will go to the refreshment room to have a glass of lemonade. (First conditional) - If we were thirsty, we would go to the refreshment room to have a glass of lemonade. (Second conditional) - If we had been thirsty, we would have gone to the refreshment room to have a glass of lemonade. (Third conditional)

4) She couldn't mend her dress herself because she had no needle. - If she has a needle, she can mend her dress herself. (First conditional) - If she had a needle, she could mend her dress herself. (Second conditional) - If she had had a needle, she could have mended her dress herself. (Third conditional)

I hope this helps you understand how to use conditionals in English.